ppxscal/embedding_network huggingface dataset:
Software Process Improvement Problems in Twelve Software Companies: An Empirical Analysis
Authors: Sarah Beecham, Tracy Hall, Austen Rainer
Venue: Empirical Software Engineering (2003)

In this paper we discuss our study of the problems 12 software companies experienced in software development. In total we present qualitative data collected from 45 focus groups that involved over 200 software staff. We look at how different practitioner groups respond to software process improvement problems. We show our classification and analysis of this data using correspondence analysis. Correspondence analysis is a graphical data representation method new to software development research. The aim of the work we present is to develop a more holistic understanding of the problems practitioners are experiencing in their attempts to improve their software processes. Our main finding is that there is an association between a company&rsquo;s capability maturity and patterns of reported problems. Organizational problems are more associated with high maturity companies than with low maturity companies. Low maturity companies are closely linked to problems relating directly to projects such as documentation, timescales, tools and technology. Our findings also confirm differences in practitioner group problems. Senior managers cite problems with goals, culture and politics. Project managers are concerned with timescales, change management, budgets and estimates. Developers are experiencing problems with requirements, testing, documentation, communication, tools and technology. These associations are displayed graphically through correspondence analysis maps.
ASEP: A Secure and Flexible Commit Protocol for MLS Distributed Database Systems
Authors: Indrajit Ray, Luigi V. Mancini, Sushil Jajodia, Elisa Bertino
Venue: IEEE Transactions on Knowledge and Data Engineering (2000)

The classical Early Prepare commit protocol (EP), used in many commercial systems, is not suitable for use in multilevel secure distributed databases systems that employ a locking protocol for concurrency control. This is because EP requires that read locks are not released by a participant during its window of uncertainty; however, it is not possible for a locking protocol to provide this guarantee in a multilevel secure system (since the read lock of a higher-level transaction on a lower-level data object must be released whenever a lower-level transaction wants to write the same data). The only available work in the literature, namely the Secure Early Prepare protocol (SEP), overcomes this difficulty by aborting those distributed transactions that release their low-level read locks prematurely. We see this approach as being too restrictive. One of the major benefits of distributed processing is its robustness to failures, and SEP fails to take advantage of this. In this work, we propose the Advanced Secure Early Prepare commit protocol (ASEP) to solve the above problem together with a number of language primitives that can be used as system calls in distributed transactions. These primitives permit features like partial rollback and forward recovery to be incorporated within the transaction model, and allow a distributed transaction to proceed even when a participant has released its low-level read locks prematurely. This not only offers flexibility, but can also be used, if desired, by a sophisticated programmer to trade off consistency for atomicity of the distributed transaction.
Synchronous C++: A Language for Interactive Applications
Authors: Claude Petitpierre
Venue: Computer (1998)

Using the Dining Philosophers problem, the author shows how Synchronous C++ can improve the development of concurrent applications. sC++ introduces the concept of an active object. The syntax of the definition, instantiation, reference, call, inheritance, and deletion of an active object is identical to the syntax of the same operations on a standard or passive object. An active object, however, contains an internal activity that runs in parallel with the activities of the other active objects. This activity can delay the executions of its methods-when called from outside-until it is ready to accept them. sC++ has strong connections to the domains of concurrency, behavior analysis, and OO programming. Namely, sC++ contains a real-time kernel, lends itself to analysis by modern modeling and analysis theories, and uses the same syntax for active objects as for passive ones. This article focuses on examples in which the dynamic and functional models dominate and the object model is secondary. In doing so, the author proposes a mapping between the elements of all three models and sC++ statements.
Toward New Software for Computational Phylogenetics
Authors: Bernard M. E. Moret, Li-San Wang, Tandy Warnow
Venue: Computer (2002)

Systematists study how a group of genes or organisms evolved. These biologists now have set their sights on the Tree of Life challenge: to reconstruct the evolutionary history of all knownliving organisms.A typical phylogenetic reconstruction starts with biomolecular data, such as DNA sequences for modern organisms, and builds a tree, or phylogeny, for these sequences that represents a hypothesized evolutionary history. Finding the best tree for a data set can be a computationally intensive problem.Phylogenetic software for mapping the Tree of Life will require entirely new approaches in statistical models of evolution, high-performance implementations, and data analysis and visualization. The authors have developed polynomial algorithmic techniques for use in their research addressing phylogeny reconstruction from biomolecular sequences, focusing on theaccuracy of reconstructions and the use of simulations.
Expert Education-Using Knowledge Engineering to Teach Science
Authors: R. A. Morelli
Venue: IEEE Expert: Intelligent Systems and Their Applications (1990)

It is shown how knowledge engineering's pedagogical potential was exploited by engaging junior-high-school students in an expert system project at Trinity College. Serving as knowledge engineers, the students developed an expert system for identifying tree species. Project evaluation indicates that students mastered target knowledge. Also, they enjoyed taking a somewhat different approach to this standard junior-high-school subject. The success of the experiment supports the view that knowledge engineering should be considered as an innovative approach for teaching scientific subjects and improving independent learning skills.
To Whom am I Speaking?
Authors: Mark Lomas, Bruce Christianson
Venue: Computer (1995)

Today's networked computer systems are very vulnerable to attack: Terminal software, like that used by the X Window System, is frequently passed across a network, and a trojan horse can easily be inserted while it is in transit. Many other software products, including operating systems, load parts of themselves from a server across a network. Although users may be confident that their workstation is physically secure, some part of the network to which they are attached almost certainly is not secure. Most proposals that recommend cryptographic means to protect remotely loaded software also eliminate the advantages of remote loading--for example, ease of reconfiguration, upgrade distribution, and maintenance. For this reason, they have largely been abandoned before finding their way into commercial products. This article shows that, contrary to intuition, it is no more difficult to protect a workstation that loads its software across an insecure network than to protect a stand-alone workstation. In contrast to prevailing practice, the authors make essential use of a collision-rich hash function to ensure that an exhaustive off- line search by the opponent will produce not one, but many candidate passwords. This strategy forces the opponent into an open, on-line guessing attack and offers the user a defensive strategy unavailable in the case of an off-line attack.
Surfactant mediated growth of MnSi1.7 layers on (001) Si
Authors: A. Mogilatenko, M. Falke, S. Teichert, H. Hortenbach, G. Beddies, H.-J. Hinneberg
Venue: Microelectronic Engineering (2002)

This study reports on transmission electron microscopy investigations of higher manganese silicide (HMS) layers grown by molecular beam epitaxy (MBE) on (001)Si using the surfactant mediated reactive deposition technique. Applying Sb as a surfactant (surface active substances) results in an increased silicide island density as well as in a change in the crystalline orientation of the silicide islands. The silicide islands were found to grow into the Si matrix. The preferential epitaxial relationship was determined to be (100)[010]Mn4Si7 || (001)[100]Si or (010)[??00]Mn4Si7 || (001)[100]Si. In [100]Si cross-sectional view the silicide crystallites of this orientation appear with a smooth Mn4Si7/(010)Si interface and a slightly inclined to (001)Si Mn4Si7/Si interface, which is suggested to split up into two local sections: Mn4Si7/(001)Si and Mn4Si7/(011)Si.
Measurements of the velocity-field characteristic in AlGaN/GaN heterostructures
Authors: J. M. Barker, D. K. Ferry, S. M. Goodnick, D. D. Koleske, A. E. Wickenden, R. L. Henry
Venue: Microelectronic Engineering (2002)

AlGaN/GaN test structures, with an etched constriction have been fabricated and tested with, and without, a gate. A pulsed voltage input with a 200 ns pulse width and a four-point measurement were used in a 50 Ω environment to determine the room temperature velocity-field characteristic of the structures. A low field mobility of 250 cm2/V s and an estimated electron velocity of ∼ 2 × 107 cm/s was attained at a field of 180 kV/cm.
On the influence of the proposal distributions on a reversible jump MCMC algorithm applied to the detection of multiple change-points
Authors: R. Rotondi
Venue: Computational Statistics Data Analysis (2002)

In this paper we address some issues arising in the implementation of Markov chain Monte Carlo methods; in particular we analyse whether the choice of transition kernels depending on a specific problem speeds up the convergence of a Metropolis-Hastings-type algorithm. This approach is applied to the retrospective detection of multiple structural changes in the physical process generating earthquakes. As the number of changes is unknown, the adopted hierarchical Bayesian model has variable-dimension parameters. The sensitivity of the method and issues related to the estimation of both the parameters and the posterior model distributions are also dealt with.
Minimizing Ecological Gaps in Interface Design
Authors: John C. Thomas, Wendy A. Kellogg
Venue: IEEE Software (1989)

The authors explore what they call an ecological gap between what is observed during interface evaluation in a laboratory and what happens when the interface is used in the real world. They look at the gap as it relates to users, tasks, systems, and the real-world context. They propose specific techniques to be used at different phases of development for evaluation and tuning the interfaces in a real-world context.
Globally Consistent Event Ordering in One-Directional Distributed Environments
Authors: Paul Ammann, Sushil Jajodia, Phyllis G. Frankl
Venue: IEEE Transactions on Parallel and Distributed Systems (1996)

We consider communication structures for event ordering algorithms in distributed environments where information flows only in one direction. Example applications are multilevel security and hierarchically decomposed databases. Although the most general one-directional communication structure is a partial order, partial orders do not enjoy the property of being consistently ordered, a formalization of the notion that local ordering decisions are ensured to be globally consistent. Our main result is that the crown-free property is necessary and sufficient for a communication structure to be consistently ordered. We discuss the computational complexity of detecting crowns and sketch typical applications.
Combinatorial Optimization of Distributed Queries
Authors: Bojan Groselj, Qutaibah M. Malluhi
Venue: IEEE Transactions on Knowledge and Data Engineering (1995)

In relational distributed databases a query cost consists of a local cost and a transmission cost. Query optimization is a combinatorial optimization problem. As the query size grows, the optimization methods based on exhaustive search become too expensive. We propose the following strategy for solving large distributed query optimization problems in relational database systems: 1) represent each query-processing schedule by a labeled directed graph, 2) reduce the number of different schedules by pruning away invalid or high-cost solutions, and 3) find a suboptimal schedule by combinatorial optimization. We investigate several combinatorial optimization techniques: random search, single start, multistart, simulated annealing, and a combination of random search and local simulated annealing. The utility of combinatorial optimization is demonstrated in the problem of finding the (sub)optimal semijoin schedule that fully reduces all relations of a tree query. The combination of random search and local simulated annealing was superior to other tested methods.
Acceleration of Nonnumeric Operations Using Hardware Support for the Ordered Table Hashing Algorithms
Authors: Emil Jovanov, Veljko Milutinovic, Ali R. Hurson
Venue: IEEE Transactions on Computers (2002)

This paper introduces a new approach to acceleration of nonnumeric, database, and information retrieval operations. While traditional techniques accelerate the most time-critical high-level software constructs, we propose novel low-level primitives and demonstrate how these primitives improve database operations. Radix sorting, hashing, and bit-vector operations are used to develop a new class of nonnumeric algorithms¿OTHER (Ordered Table Hashing and Radix sort algorithms)¿based on low-level hashing operations Init, Mark, and Scan. We have proposed and evaluated two hardware accelerators for OTHER algorithms. It is shown that a low complexity hardware support (less than 10K transistors) can significantly improve the performance of nonnumeric operations.
Area minimization of power distribution network using efficient nonlinear programming techniques
Authors: Xiaohai Wu, Xianlong Hong, Yici Cai, C. K. Cheng, Jun Gu, Wayne Dai
Venue: Proceedings of the 2001 IEEE/ACM international conference on Computer-aided design (2001)

This paper deals with area minimization of power distribution network for VLSIs. A new algorithm based on efficient nonlinear programming techniques is presented to solve this problem. The experiment results prove that this algorithm has achieved the objects that minimize the area of power/ground networks with higher speed.
Allocating Precise Submeshes in Mesh Connected Systems
Authors: P. J. Chuang, N. F. Tzeng
Venue: IEEE Transactions on Parallel and Distributed Systems (1994)

We propose a new processor allocation strategy that applies to any mesh system andrecognizes submeshes of arbitrary sizes at any locations in a mesh system. The proposedstrategy allocates a submesh of exactly the size requested by an incoming task,completely avoiding internal fragmentation. Because of its efficient allocation, thisstrategy exhibits better performance than an earlier allocation strategy based on thebuddy principle. An efficient implementation of this strategy is presented. Extensivesimulation runs are carried out to collect experimental cost and performance measures ofinterest under different allocation schemes.
Spatio-Temporal Composition of Video Objects: Representation and Querying in Video Database Systems
Authors: N. Pissinou, I. Radev, K. Makki, W. J. Campbell
Venue: IEEE Transactions on Knowledge and Data Engineering (2001)

A key characteristic of video data is the associated spatial and temporal semantics. It is important that a video model models the characteristics of objects and their relationships in time and space. Allen's 13 temporal relationships are often used in formulating queries that contain the temporal relationships among video frames. For the spatial relationships, most of the approaches are based on projecting objects on a two or three-dimensional coordinate system. However, very few attempts have been made formally to represent the spatio-temporal relationships of objects contained in the video data and to formulate queries with spatio-temporal constraints. The purpose of our work is to design a model representation for the specification of the spatio-temporal relationships among objects in video sequences. The model describes the spatial relationships among objects for each frame in a given video scene and the temporal relationships (for this frame) of the temporal intervals measuring the duration of these spatial relationships. It also models the temporal composition of an object, which reflects the evolution of object's spatial relationships over the subsequent frames in the video scene and in the entire video sequence. Our model representation also provides an effective and expressive way for the complete and precise specification of distances among objects in digital video. This model is a basis for the annotation of raw video.
A Trace-Driven Simulator for Performance Evaluation of Cache-Based Multiprocessor Systems
Authors: Cosimo Antonio Prete, Gianpaolo Prina, Luigi Ricciardi
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

We describe a simulator which emulates the activity of a shared memory, common bus multiprocessor system with private caches. Both kernel and user program activities are considered, thus allowing an accurate analysis and evaluation of coherence protocol performance. The simulator can generate synthetic traces, based on a wide set of input parameters which specify processor, kernel and workload features. Other parameters allow us to detail the multiprocessor architecture for which the analysis has to be carried out. An actual-trace-driven simulation is possible, too, in order to evaluate the performance of a specific multiprocessor with respect to a given workload, if traces concerning this workload are available. In a separate section, we describe how actual traces can also be used to extract a set of input parameters for synthetic trace generation. Finally, we show how the simulator may be successfully employed to carry out a detailed performance analysis of a specific coherence protocol.
Eco System: An Internet Commerce Architecture
Authors: Jay M. Tenenbaum, Tripatinder S. Chowdhry, Kevin Hughes
Venue: Computer (1997)

The Internet provides the first affordable and secure way to link people and computers spontaneously across organizational boundaries. But the Internet's potential is imperiled by the rising specter of digital anarchy: closed markets that cannot use each other's services; incompatible applications and frameworks that cannot interoperate or build upon each other; and an array of security and payment options that confuses consumers. One solution to these problems is an object-oriented architectural framework for Internet commerce. Several major vendors of electronic-commerce solutions have announced proprietary versions of such a framework, including IBM, Microsoft, Netscape, Oracle, and Sun/JavaSoft. Recently, four of these companies have agreed to support a common distributed object model based on CORBA IIOP (Internet InterORB Protocol). Yet for commerce on the Internet to thrive, such systems must also interoperate at a business application level. A consumer or business using one framework should be able to shop for, purchase, and pay for goods and services offered on a different framework. This is currently not possible. In response, CommerceNet is organizing Eco System, a cross-industry effort to build a framework of frameworks, involving both e-commerce vendors and end users. The success of Eco depends on market leaders in each area participating actively on their respective task forces. Admittedly, in past battles for market dominance, it was difficult to bring leading players to the table. For robust Internet commerce, however, interoperability is so fundamental that we have to turn the concept of openness on its head-it's not just publishing an API. Everyone's software has to work together because no single company can control what platform its customers will use. Internet commerce stands at a critical juncture. After an exhilarating start-up, further development hinges on bridging the chasm between early adopters and a true mass market.
Isomorphism certificates for undirected graphs
Authors: Michael Molloy, Laura Sedgwick
Venue: Discrete Mathematics (2002)

For a graph G, we are interested in a minimum-size subgraph of G which, along with an unlabelled copy of G, provides enough information to reconstruct G. We perform a preliminary study of such subgraphs, focusing on the cases where G is a complete tree or a grid.
Choices of Operand Truncation in the SRT Division Algorithm
Authors: Ted Williams, Neil Burgess
Venue: IEEE Transactions on Computers (1995)

This paper presents an analysis of the number of partial remainder digits and divisor bits that must be examined in the SRT division algorithm. The number of examined digits is found to be the same for both signed-digit and 2s-complement partial remainder representations, and appears to increase as 3log2r approximately, where r is the radix of the divider. In some cases, it proves advantageous to examine a fractional number of remainder digits by inspecting more positive than negative bits.
Reconciling the needs of architectural description with object-modeling notations
Authors: David Garlan, Shang-Wen Cheng, Andrew J. Kompanek
Venue: Science of Computer Programming (2002)

Complex software systems require expressive notations for representing their software architectures. Two competing paths have emerged. One is to use a specialized notation for architecture, an architecture description language (ADL). The other is to adapt a general-purpose modeling notation, such as UML. The latter has a number of benefits, including familiarity to developers, close mapping to implementations, and commercial tool support. However, it remains an open question as to how best to use object-oriented notations for architectural description, and, indeed, whether they are sufficiently expressive, as currently defined. In this paper, we take a systematic look at these questions, examining the space of possible mappings from ADLs into UML. Specifically, we describe (a) the principal strategies for representing architectural structure in UML; (b) the benefits and limitations of each strategy; and (c) aspects of architectural description that are intrinsically difficult to model in UML using the strategies.
Computational RAM: Implementing Processors in Memory
Authors: Duncan Elliott, Michael Stumm, W. Martin Snelgrove, Christian Cojocaru, Robert McKenzie
Venue: IEEE Design Test (1999)

Computational RAM (C·RAM) is an integrated circuit that implements a "smart memory" whereby processing elements are integrated into the memory chip. C·RAM can function either as a conventional memory chip or as a SIMD computer. When used as a memory, C·RAM is competitive with conventional DRAM in terms of access time, packaging and cost. In fact, adding processing elements to DRAM adds only 3-20% in area and 10-25% in power consumption. When used as a SIMD computer, C·RAM can run suitable parallel applications thousands of times faster than a CPU. We argue that the key to successfully integrating processing power to memory is to use an architecture that preserves and exploits the features and characteristics of memory. If effective use is to be made of the internal memory bandwidth, then adding logic to memory is not simply a question of bolting together two existing designs.