Sushll Prasad

• Georgia State University

Finding meaningful communities - subnetworks of interest within a large scale network - is a problem with a variety of applications. Most existing work towards community detection focuses on a single network. However, many real-life applications naturally yield what we refer to as Triple Networks. Triple Networks are comprised of two networks, and...

Efficient end-to-end parallel/distributed processing of vector-based spatial data has been a long-standing research question in GIS community. The irregular and data intensive nature of the underlying computation has impeded the research in this space. We have created an open-architecture-based system named Crayons for Azure cloud platform using st...

The premise of the NSF-supported Center for Parallel and Distributed Computing Curriculum Development and Educational Resources (CDER) is that every computer science (CS) and computer engineering (CE) undergraduate student should achieve a basic skill level in parallel and distributed computing (PDC). This book is a companion to our 2015 book, the...

Colocation patterns refer to subsets of spatial features whose instances are frequently located together. Mining colocation patterns is important in many applications such as identifying relationships between diseases and environmental factors, but is computationally challenging due to the large number of instances and candidate patterns. Existing...

In recent times, geospatial datasets are growing in terms of size, complexity and heterogeneity. High performance systems are needed to analyze such data to produce actionable insights in an efficient manner. For polygonal a.k.a vector datasets, operations such as I/O, data partitioning, communication, and load balancing becomes challenging in a cl...

This book introduces beginning undergraduate students of computing and computational disciplines to modern parallel and distributed programming languages and environments, including map-reduce, general-purpose graphics processing units (GPUs), and graphical user interfaces (GUI) for mobile applications. The book also guides instructors via selected...

Grid-based techniques are well-suited for spatial join algorithms over General Purpose Graphic Processing Unit (GPGPU) architectures because of their non-hierarchical structure. However, these techniques are well-established years before the existence of GPU computing. As a result, they do not fully take advantage of many-core architectures. Last y...

Given two layers of large polygonal datasets, detecting those pairs of cross-layer polygons which satisfy a join predicate, such as intersection or contain, is one of the most computationally intensive primitive operations in the spatial domain applications. In this work, we introduce GCMF, an end-to-end software system, that is able to handle spat...

This chapter starts with a brief introduction to the NSF-supported Center for Parallel and Distributed Computing Curriculum Development and Educational Resources (CDER), under whose auspices this book is being published. It discusses the motivation behind this collection as well as the organization of the collection. It also includes short introduc...

Discovery of interesting paths and regions in spatio-temporal data sets is important to many fields such as the earth and atmospheric sciences, GIS, public safety and public health both as a goal and as a preliminary step in a larger series of computations. This discovery is usually an exhaustive procedure that quickly becomes extremely time consum...

Clipping arbitrary polygons is one of the complex operations in computer graphics and computational geometry. It is applied in many fields such as Geographic Information Systems (GIS) and VLSI CAD. We have two significant results to report. Our first result is the effective parallelization of the classic, highly sequential Greiner-Hormann algorithm...

We summarize the need and present our vision for accelerating geo-spatial computations and analytics using a combination of shared and distributed memory parallel platforms, with general-purpose Graphics Processing Units (GPUs) with 100s to 1000s of processing cores in a single chip forming a key architecture to parallelize over. A GPU can yield on...

Penetration of GPS-enabled devices has resulted in the generation of a lot of Spatial-Textual data, which can be mined or analyzed to improve various location-based services. One such kind of data is Spatial-Textual sequential data (Activity-Trajectory data), i.e. a sequence of locations visited by a user with each location having a set of activiti...

Resource management and search is very important yet challenging in large-scale distributed systems like P2Pnetworks. Most existing P2P systems rely on indexing to efficiently route queries over the network. However, searches based on such indices face two key issues. First, majority of existing search schemes often rely on simply keyword based ind...

Polygon clipping is one of the complex operations in computational geometry. It is a primitive operation in many fields such as Geographic Information Systems (GIS), Computer Graphics and VLSI CAD. Sequential algorithms for this problem are in abundance in literature but there are very few parallel algorithms solving it in its most general form. We...

Message Passing Interface (MPI) has been the predominant standardized system for writing parallel and distributed applications. However, while MPI has been the software system of choice for traditional parallel and distributed computing platforms such as large compute clusters and Grid, MPI is not the system of choice for cloud platforms. The prima...

Parallelism pervades all aspects of modern computing, from in-home devices such as cell phones to large-scale supercomputers. Recognizing this - and motivated by the premise that every undergraduate student in a computer-related field should be prepared to cope with parallel computing - a working group sponsored by NSF and IEEE/TCPP, and interactin...

It is imperative that for scalable solutions of GIS computations the modern hybrid architecture comprising a CPU-GPU pair is exploited fully. The existing parallel algorithms and data structures port reasonably well to multi-core CPUs, but poorly to GPGPUs because of latter's atypical fine-grained, single-instruction multiple-thread (SIMT) architec...

Resource management is very important yet challenging in large scale distributed systems like P2P networks. With more and more users incorporating semantic meta-data with their resources, the resource discovery mechanism should not only be able to scale well with the large number of information resources but also be capable of retrieving semantical...

Polygon overlay is one of the complex operations in Geographic Information Systems (GIS). In GIS, a typical polygon tends to be large in size often consisting of thousands of vertices. Sequential algorithms for this problem are in abundance in literature and most of the parallel algorithms concentrate on parallelizing edge intersection phase only....

Polygon overlay is one of the complex operations in computational geometry. It is applied in many fields such as Geographic Information Systems (GIS), computer graphics and VLSI CAD. Sequential algorithms for this problem are in abundance in literature but there is a lack of distributed algorithms especially for MapReduce platform. In GIS, spatial...

Windows Azure is an emerging cloud platform that provides application developers with APIs to write scientific and commercial applications. However, the steep learning curve to understand the unique architecture of the cloud platforms in general and continuously changing Azure APIs specifically, make it difficult for the application developers to w...

The paper is devoted to Time Division Multiple Access Link Scheduling Protocols in wireless sensor networks for full duplex (two-way) communication, where each sensor is scheduled on an incident link as a transmitter and as a receiver in two different time slots. We formulate the full duplex link scheduling problem (FDLSP) as distance-2 edge colori...

Efficient searching for information is an important goal in unstructured peer-to-peer (P2P) networks. While several P2P systems have been proposed for data sharing purposes, many support only semantics-free keyword searches or coarser grained file name searches. In this paper, we present an ontology based semantic query routing algorithm that perfo...

An efficient parallel priority queue is at the core of the effort in parallelizing important non-numeric irregular computations such as discrete event simulation scheduling and branch-and-bound algorithms. GPGPUs can provide powerful computing platform for such non-numeric computations if an efficient parallel priority queue implementation is avail...

Bilateral filtering is an ubiquitous tool for several kinds of image processing applications. This work explores multicore and many core accelerations for the embarrassingly parallel yet compute-intensive bilateral filtering kernel. For many core architectures, we have created a novel pair-symmetric algorithm to avoid redundant calculations. For mu...

Spatial overlay processing is a widely used compute-intensive GIS application that involves aggregation of two or more layers of maps to facilitate intelligent querying on the collocated output data. When large GIS data sets are represented in polygonal (vector) form, spatial analysis runs for extended periods of time, which is undesirable for time...

The paper is devoted to Time Division Multiple Access Link Scheduling Protocols in wireless sensor networks for full duplex (two-way) communication, where each sensor is scheduled on an incident link as a transmitter and as a receiver in two different time slots. We formulate the full duplex link scheduling problem (FDLSP) as distance-2 edge colori...

We here present two probabilistic edge coloring algorithms for a message passing model of distributed computing. The algorithms use a simple automata for finding a matching on a graph to produce the colorings. Our first algorithm for edge coloring finds an edge coloring of a graph which is guaranteed to use no more than 2Δ - 1 colors and completes...

Cloud computing is becoming mainstream for High Performance Computing (HPC) application development over the last few years. However, even though many vendors have rolled out their commercial cloud infrastructures, the service offerings are usually only best-effort based, without any performance guarantees. Cloud computing effectively saves the eSc...

GIS polygon-based (also know as vector-based) spatial data overlay computation is much more complex than raster data computation. Processing of polygonal spatial data files has been a long standing research question in GIS community due to the irregular and data intensive nature of the underlying computation. The state-of-the-art software for overl...

A consistent problem with distributed algorithms for graph problems is scalability. Here we present a scalable automata that can easily be modified to solve a number of problems. We focus on the Minimum Weighted Vertex Cover problem, showing that our approach improves on the best known algorithm, reducing the number of communication rounds from O(l...

Efficient searching for information is an important goal in peer-to-peer (P2P) networks. Searching in an unstructured P2P network is particularly challenging due to the random nature of the P2P overlay links. In this paper, we propose a novel probabilistic search mechanism called SPUN, that increases the success ratio of queries while keeping the b...

Presents the welcome message from the conference proceedings.

1. SUMMARY This special session will be our first formal curriculum committee report. A working group from IEEE Technical Committee on Parallel Processing (TCPP), National Science Foundation (NSF), and the sister communities, including ACM, has taken up proposing curriculum for computer science (CS) and computer engineering (CE) undergraduates on p...

Today’s web applications are more collaborative and utilize standard and ubiquitous Internet protocols. We have earlier developed System on Mobile Devices (SyD) middleware to rapidly develop and deploy collaborative applications over heterogeneous and possibly mobile devices hosting web objects. In this paper, we present the software engineering me...

The basic unit of any nervous system is the neuron. Therefore, understanding the operation of nervous systems ultimately requires an inventory of their constituent neurons and synaptic connectivity, which form neural circuits. The presence of uniquely identifiable neurons or classes of neurons in many invertebrates has facilitated the construction...

In this paper, we present two distributed algorithms to maximize the lifetime of Wireless Sensor Networks for target coverage when the sensors have the ability to adjust their sensing and communication ranges. These algorithms are based on the enhancement of distributed algorithms for fixed range sensors proposed in the literature. We outline the a...

A key problem in Wireless Sensor Networks is that of scheduling sensors into sleep-sense cycles that maximize the lifetime of the network while ensuring coverage of a set of targets. This is a known NP-complete problem, due to the exponential number of possible ways to select a subset of sensors to turn on. Our earlier work had presented a unique m...

One of the fundamental problems involving DNA sequences is to find high density segments of certain widths, for example, those regions with intensive guanine and cytosine (GC). Formally, given a sequence, each element of which has a value and a width, the maximum-density segment problem asks for the segment with the maximum density while satisfying...

Data aggregation is an essential yet time-consuming task in wireless sensor networks (WSNs). This paper studies the well-known Minimum-Latency Aggregation Schedule (MLAS) problem and proposes an energy-efficient distributed scheduling algorithm named Clu-DDAS based on a novel cluster-based aggregation tree. Our approach differs from all the previou...

One of the key challenges in wireless sensor networks (WSNs) is that of extending the lifetime of the network while meeting some coverage requirements. In this paper, we present a distributed algorithmic framework to enable sensors to determine their sleep-sense cycles based on specific coverage goals. The framework is based on our earlier work on...

Several classes of emerging applications, spanning domains such as medical informatics, homeland security, mobile commerce, and scientific applications, are collaborative, and a significant portion of these will harness the capabilities of both the stable and mobile infrastructures (the “mobile grid”). Currently, it is possible to develop a collabo...

In Grids, users may require assurance for completing their jobs on shared resources. Such guarantees can only be provided by reserving resources in advance. However, if many reservation requests arrive at a resource simultaneously, the overhead of providing such service due to adding, deleting, and searching, will be signicant. An efcient data stru...

A major challenge in Wireless Sensor Networks is that ofmaximizing the lifetime while maintaining coverage of a set of targets,a known NP-complete problem. In this paper, we present theoretically-grounded, energy-efficient, distributed algorithms that enable sensors toschedule themselves into sleep-sense cycles. We had earlier introduceda lifetime...

This paper discusses a layered workflow software architecture for distributed coordination of workflows over Web services and proposes fundamental enhancements to the web services infrastructure that facilitate the layered workflow software architecture. We verify our layered approach using a detailed simulation and a proof-of-concept prototype imp...

One of the key challenges in Wireless Sensor Networks (WSNs) is that of extending the lifetime of the network while meeting some coverage requirements. In this paper we present a distributed algorithmic framework to enable sensors to determine their sleep-sense cycles based on specific coverage goals. The framework is based on our earlier work on t...

Motivated by the need to support concurrent, collaborative access to shared documents, we have designed and validated an architecture that integrates existing and familiar systems for client editing software and document repositories. Through Web-services, we achieve an open system wherein numerous clients can use varied editing tools to fit their...

The current state of the art of workflow composition over web services employ a centralized composite process to coordinate the constituent web services. Therefore, the coordinator process is complex, less scalable, and bulky. This paper introduces an architecture and associated techniques for distributed coordination of these workflows, and a prot...

We present a new set of distributed algorithms for scheduling sensors to enhance the total lifetime of a wireless sensor network. These algorithms are based on constructing minimal cover sets each consisting of one or more sensors which can collectively cover the local targets. Some of the covers are heuristically better than others for a sensor tr...

This paper presents our work in combining peer-to-peer dynamic tree management with hierarchical Operational Transformation (OT) over document trees to achieve low computational and communication costs. We discuss our approach in storing the document tree in a peer-to-peer, distributed manner and maintaining convergence, causality preservation, and...

Knowledge of neuronal circuitry is foundational to the neurosciences, but no tools have been developed for cataloguing this knowledge. Part of the problem is that the concepts used to describe neural circuits are rapidly evolving and vary substantially across different species. The NeuronBank project (http://neuronbank.org) is developing an informa...

Parallelization of sequential programs is often daunting because of the substantial development cost involved. Previous solutions have not always been successful, partly because many try to address all types of applications. We propose a platform for parallelization of a class of applications that have similar computational structure, namely graph-...

In collaborative applications, participants agree on certain level of secure communication based on communi- cation policy specifications. Given secure communication policy specifications of various group members at design time, the minimum set of resources for a pair, called Resolved Policy Level Agreement (RPLA) is translated into appropriate sec...

Real-time collaborative editing systems allow multiple users to synchronously edit a shared document in a geographically-distributed environment. In order to maintain high responsiveness, a distributed copy model is used wherein each user maintains a local copy of the shared document; as a result, techniques such as Operation Transformation (OT) ar...

The primary goals in a synchronous collaborative editing system (CES) involve ensuring a high level of concurrent access while maintaining the properties of the CCI model. We revisit the idea of applying lock-based concurrency control algorithms to manage access to a shared document; this research overcomes the traditional problem of reduced concur...

In this paper, we consider the problem of maximizing the lifetime of a target-covering sensor network in which each sensor can adjust its sensing range. The network model consists of a large number of sensors with adjustable sensing ranges being deployed to monitor a set of targets. Since more than one sensor can cover a target, in order to be ener...

In this paper we study the problem of assigning transmission ranges to the nodes of a static ad hoc wireless network so as to minimize the total power consumed under the constraint that enough power is provided to the nodes to ensure that the network is connected. We focus on the Min-Power Symmetric Connectivity problem, in which the bidirectional...

Structured peer-to-peer systems are popular solutions for large scale distributed computing and query processing. Heterogeneity among peers calls for peer virtualization to maintain a simple, yet powerful peer-to-peer overlay network. Nevertheless, peer virtualization generates a huge number of virtual peers and causes the unnecessary communication...

The current state of the art of workflows over Web services employs a centralized composite process to coordinate the constituent Web services. Therefore, the coordinator process is complex, less scalable, and bulky. This paper introduces an architecture and a technique for distributing the centralized coordination logic of traditional workflows by...

This paper discusses our work in combining dynamic locking with operational transformation (OT) to achieve low computational and communication costs in maintaining a real-time, synchronous collaborative editing system. We discuss our approach in storing the document in a distributed, hierarchical tree and maintaining consistency, causality preserva...

The primary goals in a synchronous collaborative editing system (CES) involve ensuring a high level of concurrent access (editability) to users while maintaining the properties of the CCI model (consistency, causality-preservation, and intention-preservation). We present a system that enables CCI-compliant synchronous editing of a shared document b...

We envision users discovering suitable Web objects and configuring them on-the-fly with their desired high-level application logic, with the programming and deployment carried out entirely on the Web. Easy configurability and interplay of Web entities implies evolution of a few common sense, yet powerful set of core primitives for effective coordin...

We recently developed "system on mobile devices" (SyD) middleware for rapidly developing and deploying collaborative distributed applications over a collection of autonomous Web objects and data-stores, independent of the underlying device, data, or network. SyDListener is a key component of SyD middleware. SyDListener provides a set of interfaces...

Future Web applications will be more collaborative and will use the standard and ubiquitous Internet protocols. We have previously developed system on mobile devices (SyD) middleware to rapidly develop and deploy collaborative applications over heterogeneous and possibly mobile devices hosting web objects. In this paper, we present the software eng...

Filtering is a popular approach to reduce information traffic in subscription-based systems, especially if most subscribers are located on mobile devices. The filters are placed between the subscribers and the subscription server. With increasing number of filters from subscribers, filtering may become a bottleneck and challenge the scalability of...

In this paper, we describe recent work in developing a peer-to- peer collaborative environment. The study examines various locking mechanisms/policies by adjusting the granularity of the locked space within the shared document. Additionally, as the interface is highly dependent upon user input/interaction rather than CPU computation, the communicat...

Recently, researchers have proposed many models using reconfigurable optically pipelined buses. Most algorithms developed for these models assume that a healthy system is available. The only previous work in this area considers faulty processors or hardware for an N-processor linear array with a reconfigurable pipelined bus system (LARPBS), resulti...

Today's collaborative applications over the web span domains as diverse as enterprise e-commerce applications and biomedical applications. We have previously developed and formally investigated "Web Coordination Bonds," a theoretically powerful artifact for interconnecting autonomous web objects for control and data flows, and for enforcing depende...

Developing collaborative applications over the Web has become increasingly important. In order to accomplish this, Web services need to be extended beyond the basic service architecture (invoke and respond) to self-coordinating Web processes collaborating among themselves (transient to long lasting). A core set of artifacts is needed to allow these...

We describe a new scheme for enabling concurrent read and exclusive write access to a shared document while maximizing concurrent collaboration and removing the need to merge multiple disparate versions of the document. We employ a multi-granular, hierarchical locking mechanism by breaking the shared document into sections and subsections and repre...

Developing a collaborative application running on a collection of heterogeneous, possibly mobile, devices, each potentially hosting data stores, using existing middleware technologies such as JXTA, BREW, compact .NET and J2ME requires too many ad-hoc techniques as well as cumbersome and time-consuming programming. Our System on Mobile Devices (SyD)...

A Middleware is the software that assists an application to interact or communicate with other applications, networks, hardware, and/or operating systems. We have earlier proposed an RMI-based mid- dleware for mobile devices called System on Mobile Devices (SyD). A middleware on mobile devices is a challenging issue, as it has to deal with problems...

Our Web-based interactive game-playing-oriented college selection system acts as a smart advisor/mentor and helps students, parents, and teachers use an effective graphical user interface to efficiently search college information and to make good decisions at each stage of students' academic development. It is an expert agent with hierarchical fuzz...