ppxscal/embedding_network huggingface dataset:
A remark on Bartels and Conn's linearly constrained, discrete l1 problems
Authors: Roger W. Koenker, Pin T. Ng
Venue: ACM Transactions on Mathematical Software (TOMS) (1996)

Two modifications of Bartels and Conn's algorithm for solving linearly constrained discrete l1 problems are described. The modifications are designed to improve performance of the algorithm under conditions of degeneracy.
Limited nondeterminism
Authors: Judy Goldsmith, Matthew A. Levy, Martin Mundhenk
Venue: ACM SIGACT News (1996)

Yes, the lucky 13th column is here, and it is a guest column written by J. Goldsmith, M. Levy, and M. Mundhenk on the topic of limited nondeterminism---classes and hierarchies derived when nondeterminism itself is viewed as a quantifiable resource (as it indeed is!).Coming up in the Complexity Theory Column in the very special 100th issue of SIGACT News: A forum on the future of complexity theory. Many of the field's leading lights share their exciting insights on what lies ahead, so please be there in three!
$O(M.N)$ Algorithms for the Recognition and Isomorphism Problems on Circular-Arc Graphs
Authors: Wen-Lian Hsu
Venue: SIAM Journal on Computing (1995)

Circular-arc graphs have a rich combinatorial structure. The circular endpoint sequence of arcs in a model for a circular-arc graph is usually far from unique. We present a natural restriction on these models to make it meaningful to define the unique representations for circular-arc graphs. We characterize those circular-arc graphs which have unique restricted models and give an $O(m \cdot n)$ algorithm for recognizing circular-arc graphs. We think a more careful implementation could reduce the complexity to $O(n^2)$. Our approach is to reduce the recognition problem of circular-arc graphs to that of circle graphs. This approach has the following advantages: it is conceptually simpler than Tucker's $O(n^3)$ recognition algorithm; it exploits the similarity between circle graphs and circular-arc graphs in a natural fashion; it yields an isomorphism algorithm. A main contribution of this result is an illustration of the transformed decomposition technique. The decomposition tree developed for circular-arc graphs generalizes the concept of the PQ-tree, which is a data structure that keeps track of all possible interval representations of a given interval graph. As a consequence, our approach also yields an $O(m \cdot n)$ isomorphism algorithm for circle graphs.
A flexible operation execution model for shared distributed objects
Authors: Saniya Ben Hassen, Irina Athanasiu, Henri E. Bal
Venue: ACM SIGPLAN Notices (1996)

Many parallel and distributed programming models are based on some form of shared objects, which may be represented in various ways (e.g., single-copy, replicated, and partitioned objects). Also, many different operation execution strategies have been designed for each representation. In programming systems that use multiple representations integrated in a single object model, one way to provide multiple execution strategies is to implement each strategy independently from the others. However, this leads to rigid systems and provides little opportunity for code reuse. Instead, we propose a flexible operation execution model that allows the implementation of many different strategies, which can even be changed at runtime. We present the model and a distributed implementation of it. Also, we describe how various execution strategies can be expressed using the model, and we look at applications that benefit from its flexibility.
Selecting sequence numbers
Authors: Raymond S. Tomlinson
Venue: ACM SIGCOMM Computer Communication Review (1995)

A characteristic of almost all communication protocols is the use of unique numbers to identify individual pieces of data. These identifiers permit error control through acknowledgement and retransmission techniques. Usually successive pieces of data are identified with sequential numbers and the identifiers are thus called sequence numbers.This paper discusses techniques for selecting and synchronizing sequence numbers such that no errors will occur if certain network characteristics can be bounded and if adequate data error detection measures are taken. The discussion specifically focuses on the protocol described by Cerf and Kahn (1), but the ideas are applicable to other similar protocols.
SIMOBJECT: from rapid prototype to finished model&mdash;a breakthrough in graphical model building
Authors: Jeffry Jones
Venue: Proceedings of the 27th conference on Winter simulation (1995)

SIMOBJECT is a portable, model-building framework of objects embedded in a graphical editing environment. This framework facilitates the prototyping of systems as diverse as communications or transportation networks, manufacturing processes and business operations. OBJECT.MGR, the graphical object editor, is used to extend these prototypes and evolve them into detailed applications as more is learned about the system that is being simulated.
Organization domain modeling (ODM): formalizing the core domain modeling life cycle
Authors: Mark A. Simos
Venue: ACM SIGSOFT Software Engineering Notes (1995)

Researchers and practitioners are looking for systematic ways of comparing domain analysis (DA) methods. Comparisons have often focused on linkage between DA methods and related technologies such as systems modeling. Less attention has been paid to comparing DA methods in terms of certian core methodological issues, including problems of scoping, contextualizing, descriptive vs. prescriptive modeling, and formalized models of variability. This paper presents key aspects of Organization Domain Modeling (ODM), a systematic domain analysis method structured in terms of a core domain modeling life cycle directly addressing these methodological concerns.
Forcing Linearity on Greedy Codes
Authors: Jeffrey T. Bonn
Venue: Designs, Codes and Cryptography (1996)

Described in this paper are two different methods of forcing greedy codes to be linear over arbitrary finite fields. Both methods are generalizations of the binary B-greedy codes as well as the triangular greedy codes over arbitrary fields. One method generalizes to arbitrary orderings over arbitrary finite fields while the other method generalizes theB -greedy codes to linear codes over arbitrary finite fields. Examples of the first method are computed for triangular greedy codes. These examples give codes similar to triangular codes from B-orderings. Both methods are shown to be substantially different.
Position paper: software architectures for cooperative systems
Authors: David Mitchell
Venue: ACM SIGOIS Bulletin (1995)

We have been developing desktop conferencing systems at IBM Hursley for the last 5 years. An early version [1] was first demonstrated at Telecom '91 in Geneva (and later was a prize winner in the 1993 British Computer Society awards), while the IBM Person to Person product has been available since early 1993. Our current work centres on Lakes, an architecture [2, 3, 4, 5] for collaborative working developed to support a wide range of collaborative applications of the "same time/different place" variety across different platforms and communications media.The Lakes application programming interface is designed to allow applications to: bull; initiate peer applications and share resources, on a variety of hardware and software platforms, located on nodes across a diverse and complex communications network. bull; define multiple dedicated logical data channels between shared applications, suitable for a broad range of multimedia traffic, independent of the structure of the underlying physical network. bull; serialize, synchronize, merge or copy the data streaming between shared applications. bull; support a range of attached devices and to allow the interception and redirection of the device data.Four key issues influenced the design of Lakes:1. it should be flexible2. it should allow the creation of intelligent networks3. it should support interoperability4. application programming should be as simple as possibleWe believe these issues are extremely important in the design of co-operative systems generally. Each of them is discussed below.
An SBus monitor board
Authors: H. A. Xie, K. E. Forward, K. M. Adams, D. Leask
Venue: Proceedings of the 1995 ACM third international symposium on Field-programmable gate arrays (1995)

During the development of computer peripherals which interface to the processor via the system bus it is often necessary to acquire the signals on the bus at the hardware level. It is difficult to attach general-purpose logic analysers and in-circuit emulators to a multiple pin bus connector and hence it is not practical to catch all the bus data required to ensure that such signals are in accordance with the bus specification. Hence a given connector specific bus monitor board is a necessary instrument to attach to the system motherboard in order to monitor all bus activities. A connector specific bus monitor board provides an efficient resource with which to study the internal philosophy of system software, the software implementation process for different communication layers, and to provide debugging for hardware developers. The bus monitor board described here is designed to attach to a SUN SBus and is similar to the Transformable Computer, which appeared recently, in that its architecture is reconfigurable via the use of a Field Programmable Gate Array (FPGA). It can be programmed to customise it to various users' specific needs. It differs from the Transformable Computer in that although it can be programmed to function as a coprocessor its primary function is dedicated SBus Monitoring. It is less costly than a Transformable Computer.In this article we describe the prototype of an SBus monitor's architecture and functions, and present the experimental results obtained from a Sun SPARC work station and an Aurora SBox Expansion Chassis, which demonstrate its ability to capture and display data communication and bus activity. Since this prototype board is programmable, it has the potential to provide many special purpose SBus monitors, but also function as a programmable coprocessor.
Hierarchical distance-vector multicast routing for the MBone
Authors: Ajit S. Thyagarajan, Stephen E. Deering
Venue: Proceedings of the conference on Applications, technologies, architectures, and protocols for computer communication (1995)

The exponential growth of the Multicast Back-bone (MBone) has resulted in increased routing overhead and processing costs. In this paper we propose a two-level hierarchical routing model as a solution to this problem. This approach involves partitioning the MBone into non-overlapping regions using DVMRP as the inter-region routing protocol; intra-region routing may be accomplished by any of a number of existing multicast protocols. Our design is flexible enough to accommodate additional levels of hierarchy, and protocols other than DVMRP at the higher levels. The unique feature of this approach is the independence of the higher level routing protocol from the subnet addresses, which allows for easy incremental deployment with small changes to existing intra-region protocols.
Parts of Visual Form: Computational Aspects
Authors: Kaleem Siddiqi, Benjamin B. Kimia
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

Underlying recognition is an organization of objects and their parts into classes and hierarchies. A representation of parts for recognition requires that they be invariant to rigid transformations, robust in the presence of occlusions, stable with changes in viewing geometry, and be arranged in a hierarchy. These constraints are captured in a general framework using notions of a PART-LINE and a PARTITIONING SCHEME. A proposed general principle of ¿form from function¿ motivates a particular partitioning scheme involving two types of parts, NECK-BASED and LIMB-BASED, whose psychophysical relevance was demonstrated in [39]. Neck-based parts arise from narrowings in shape, or the local minima in distance between two points on the boundary, while limb-based parts arise from a pair of negative curvature minima which have ¿co-circular¿ tangents. In this paper, we present computational support for the limb-based and neck-based parts by showing that they are invariant, robust, stable and yield a hierarchy of parts. Examples illustrate that the resulting decompositions are robust in the presence of occlusion and clutter for a range of man-made and natural objects, and lead to natural and intuitive parts which can be used for recognition.
Digital library services in mobile computing
Authors: Bharat Bhargava, Melliyal Annamalai, Evaggelia Pitoura
Venue: ACM SIGMOD Record (1995)

Digital libraries bring about the integration, management, and communication of gigabytes of multimedia data in a distributed environment. Digital library systems currently envision users as being static when they access information. But it is expected in the near future that tens of millions of users will have access to a digital library through wireless access. Providing digital library services to users whose location is constantly changing, whose network connections are through a wireless medium, and whose computing power is low necessitates modifications to existing digital library systems. In this paper, we identify the issues that arise when users are mobile, classify queries that are specific to mobile users and introduce an architecture that supports flexible and transparent access to digital libraries for mobile users. The main features of the architecture include a layered data representation, support of adaptability, dual broadcast and on demand querying, caching, and mobile-specific user interfaces.
A reference architecture for multi-author World-Wide Web servers
Authors: Louis Perrochon
Venue: Proceedings of conference on Organizational computing systems (1995)

Designing publicly accessible and distributed information structures and coordinating distributed authors is a major challenge for most organizations. This paper presents a scaleable reference architecture for multi-author World-Wide Web (W3) servers, one important type of a distributed and publicly accessible information system. We introduce the paradigm of &ldquo;lean production of information&rdquo; and discuss some problems of data quality regarding W3-servers. Experiences made with a departmental W3-server designed and maintained according to the principles presented are appended as a case study.
Recovery in the Calypso file system
Authors: Murthy Devarakonda, Bill Kish, Ajay Mohindra
Venue: ACM Transactions on Computer Systems (TOCS) (1996)

This article presents the deign and implementation of the recovery scheme in Calypso. Calypso is a cluster-optimized, distributed file system for UNIX clusters. As in Sprite and AFS, Calypso servers are stateful and scale well to a large number of clients. The recovery scheme in Calypso is nondisruptive, meaning that open files remain open, client modified data are saved, and in-flight operations are properly handled across server recover. The scheme uses distributed state amount the clients to reconstruct the server state on a backup node if disks are multiported or on the rebooted server node. It guarantees data consistency during recovery and provides congestion control. Measurements show that the state reconstruction can be quite fast: for example, in a 32-node cluster, when an average node contains state for about 420 files, the reconstruction time is about 3.3 seconds. However, the time to update a file system after a failure can be a major factor in the overall recovery time, even when using journaling techniques.
Fast Algorithms for Confluent Vandermonde Linear Systems and Generalized Trummer's Problem
Authors: Hao Lu
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

Asymptotically fast algorithms for both dual confluent Vandermonde linear systems and generalized Trummer's problem are presented by using the divide and conquer method. It is shown that dual confluent Vandermonde linear systems can be solved in $O(n \log n \log p)$ operations and generalized Trummer's problem can be done in $O(np \log n \log \frac{n}{p})$ operations if fast polynomial multiplication and division are used. Also a fast algorithm for Hermite evaluation of rational functions is presented.
BPMS: business process management systems
Authors: Dimitris Karagiannis
Venue: ACM SIGOIS Bulletin (1995)

In the last years a lot of research has been done in different domains concerning information system applications. Recent research is characterized by the effort of applying information systems to heterogeneous and distributed environments. Information systems dealing with the definition, administration, customization and evaluation of tasks evolving from business processes as well as from organizational structures are called Business Process Management Systems (BPMS).Recognizing the need of such systems a lot of software companies are entering the markets with first innovative products, based on workflow-based technology, called Workflow Management Systems (WMS). These products have the ability to define and control the workflow in an organization, transfer data, and integrate legacy information systems, existing programs and program modules with the goal of facilitating a vendor's transformation to a "professional services" focus [Sil 95].The main idea of WMS can be described in one simple sentence: Existing Workflow Management Systems are the 1st Generation of BPMS and have the ability to delegate business tasks to the right people at the right time using the right information resources.A BPMS can achieve such a goal only if it offers various task management services. Among these services, the appropriate modeling of the business processes and underlying organizations is the most essential. Support for analysis in order to verify, evaluate and modify processes and organizational structures is also of great importance. Furthermore, a BPMS should support the use of knowledge concerning the awareness/unawareness of integrated software.
An algebra approach to the deduction of data flow diagrams and object oriented diagrams from algebraic specifications
Authors: Federico Vazquez
Venue: ACM SIGSOFT Software Engineering Notes (1996)

The Software Engineering procedures usually lack formal mathematical foundations. This paper presents a formal approach for the development of Specifications, Data Flow Diagrams and Object Oriented Diagrams using algebraic theory. The use of algebraic theory allows the check for completeness and consistency and the generation of automatic procedures for translating specifications into Data Flow Diagrams or Object Oriented Diagrams.
S-connect: from networks of workstations to supercomputer performance
Authors: Andreas G. Nowatzyk, Michael C. Browne, Edmund J. Kelly, Michael Parkin
Venue: ACM SIGARCH Computer Architecture News (1995)

S-Connect is a new high speed, scalable interconnect system that has been developed to support networks of workstations to efficiently share computing resources. It uses off-the-shelf CMOS technology to directly drive fiber-optic systems at speeds greater than 1 Gbit/sec and can realize bisection bandwidths comparable to high-end MPP systems while being gt;10x more cost-effective. S-Connect systems do not rely on centralized switches, but rather are composed of adaptive, topology independent routing elements that are integrated into each node. The S-Connect routing algorithm is optimized for fine grained, irregular traffic and is designed to support high traffic loads, that can utilize most of the physically available bandwidth. Such traffic is typical of a distributed shared memory system, which is one of the intended applications. S-Connect innovations include a novel distributed phase locking method that allows global synchronization, HW support for multiple message priorities, in-band monitoring and control facilities, and a low overhead channel protocol that supports multiple in-transit messages on the same fiber.The first version of the S-Connect switching element has been successfully implemented in a commercial, 0.65 micro;m CMOS process.
Reconciling responsiveness with performance in pure object-oriented languages
Authors: Urs Hölzle, David Ungar
Venue: ACM Transactions on Programming Languages and Systems (TOPLAS) (1996)

Dynamically dispatched calls often limit the performance of object-oriented programs, since opject-oriented programming encourages factoring code into small, reusable units, thereby increasing the frequency of these expensive operations. Frequent calls not only slow down execution with the dispatch overhead per se, but more importantly they hinder optimization by limiting the range and effectiveness of standard global optimizations. In particular, dynamically dispatched calles prevent standard interprocedual optimizations that depend on the availability of a static call graph. The SELF implementation described here offers tow novel approaches to optimization. Type feedback speculatively inlines dynamically dispatched calls based on profile information that predicts likely receiver classes. Adaptive optimization reconciles optimizing compilation with interactive performance by incrementally optimizing only the frequently executed parts of a program. When combined, these two techniques result in a system that can execute programs significantly faster than previous systems while retaining much of the interactiveness of an interpreted system.
An annotated bibliography of benchmarks for object databases
Authors: Akmal B. Chaudhri
Venue: ACM SIGMOD Record (1995)

This annotated bibliography presents a collection of published papers, technical reports, Master's and PhD Theses that have investigated various aspects of object database performance.
Uniqueness of Solutions to Three Perspective Views of Four Points
Authors: Robert J. Holt, Arun N. Netravali
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

We show that there is, in general, a unique solution for the relative orientation of three cameras simultaneously photographing four feature points on a fixed object. However, multiple solutions are possible, in rare cases, even when the four feature points are not coplanar.
GURRR: a global unified resource requirements representation
Authors: David A. Berson, Rajiv Gupta, Mary Lou Soffa
Venue: ACM SIGPLAN Notices (1995)

When compiling for instruction level parallelism (ILP), the integration of the optimization phases can lead to an improvement in the quality of code generated. However, since several different representations of a program are used in the various phases, only a partial integration has been achieved to date. We present a program representation that combines resource requirements and availability information with control and data dependence information. The representation enables the integration of several optimizing phases, including transformations, register allocation, and instruction scheduling. The basis of this integration is the simultaneous allocation of different types of resources. We define the representation and show how it is constructed. We then formulate several optimization phases to use the representation to achieve better integration.
Computationally complicated problems of numerical computations (in particular, interval computations), biofeedback, computer games, and Gulf War: an idea
Authors: Misha Koshelev
Venue: ACM SIGNUM Newsletter (1996)

Many problems of numerical computations are computationally intractable (or, to use a precise term from theoretical computer science, NP-hard; for precise definitions, see, e.g., [2]). From a practical viewpoint, this means that no feasible algorithm can solve all instances of such problems.