ppxscal/embedding_network huggingface dataset:
Simple Fast Parallel Hashing by Oblivious Execution
Authors: Joseph Gil, Yossi Matias
Venue: SIAM Journal on Computing (1998)

A hash table is a representation of a set in a linear size data structure that supports constant-time membership queries. We show how to construct a hash table for any given set of n keys in O(lg lg n) parallel time with high probability, using n processors on a weak version of a concurrent-read concurrent-write parallel random access machine (crcw pram). Our algorithm uses a novel approach of hashing by "oblivious execution" based on probabilistic analysis. The algorithm is simple and has the following structure: Partition the input set into buckets by a random polynomial of constant degree. For t:= 1 to O(lg lg n) do Allocate Mt memory blocks, each of size Kt. Let each bucket select a block at random, and try to injectively map its keys into the block using a random linear function. Buckets that fail carry on to the next iteration. The crux of the algorithm is a careful a priori selection of the parameters Mt and Kt. The algorithm uses only O(lg lg n) random words and can be implemented in a work-efficient manner.
Robotics for Plant Production
Authors: Naoshi Kondo, K. C. Ting
Venue: Artificial Intelligence Review (1998)

Applying robotics in plant production requires the integration of robot capabilities, plant culture, and the work environment. Commercial plant production requires certain cultural practices to be performed on the plants under certain environmental conditions. Some of the environmental conditions are mostly natural and some are modified or controlled. In many cases, the required cultural practices dictate the layout and materials flow of the production system. Both the cultural and environmental factors significantly affect when, where and how the plants are manipulated. Several cultural practices are commonly known in the plant production industry. The ones which have been the subject of robotics research include division and transfer of plant materials in micropropagation, transplanting of seedlings, sticking of cuttings, grafting, pruning, and harvesting of fruit and vegetables. The plants are expected to change their shape and size during growth and development. Robotics technology includes many sub-topics including the manipulator mechanism and its control, end-effector design, sensing techniques, mobility, and workcell development. The robots which are to be used for performing plant cultural tasks must recognize and understand the physical properties of each unique object and must be able to work under various environmental conditions in fields or controlled environments. This article will present some considerations and examples of robotics development for plant production followed by a description of the key components of plant production robots. A case study on developing a harvesting robot for an up-side-down single truss tomato production system will also be described.
The predictability of data values
Authors: Yiannakis Sazeides, James E. Smith
Venue: Proceedings of the 30th annual ACM/IEEE international symposium on Microarchitecture (1997)

The predictability of data values is studied at a fundamental level. Two basic predictor models are defined: Computational predictors perform an operation on previous values to yield predicted next values. Examples we study are stride value prediction (which adds a delta to a previous value) and last value prediction (which performs the trivial identity operation on the previous value); Context Based} predictors match recent value history (context) with previous value history and predict values based entirely on previously observed patterns. To understand the potential of value prediction we perform simulations with unbounded prediction tables that are immediately updated using correct data values. Simulations of integer SPEC95 benchmarks show that data values can be highly predictable. Best performance is obtained with context based predictors; overall prediction accuracies are between 56% and 91%. The context based predictor typically has an accuracy about 20% better than the computational predictors (last value and stride). Comparison of context based prediction and stride prediction shows that the higher accuracy of context based prediction is due to relatively few static instructions giving large improvements; this suggests the usefulness of hybrid predictors. Among different instruction types, predictability varies significantly. In general, load and shift instructions are more difficult to predict correctly, whereas add instructions are more predictable.
Delay analysis for forward signaling channels in wireless cellular network
Authors: Izhak Rubin, Cheon Won Choi
Venue: Wireless Networks (1997)

We consider connection-oriented wireless cellular networks. Such second generation systems are circuit-switched digital networks which employ dedicated radio channels for the transmission of signaling information. A forward signaling channel is a common signaling channel assigned to carry the multiplexed stream of paging and channel-allocation packets from a base station to the mobile stations. Similarly, for ATM wireless networks, paging and virtual-circuit-allocation packets are multiplexed across the forward signaling channels as part of the virtual-circuit set-up phase. The delay levels experienced by paging and channel-allocation packets are critical factors in determining the efficient utilization of the limited radio channel capacity. A multiplexing scheme operating in a &ldquo;slotted mode&rdquo; can lead to reduced power consumption at the handsets, but may in turn induce an increase in packet delays. In this paper, focusing on forward signaling channels, we present schemes for multiplexing paging and channel-allocation packets across these channels, based on channelization plans, access priority assignments and paging group arrangements. For such multiplexing schemes, we develop analytical methods for the calculation of the delay characteristics exhibited by paging and channel-allocation packets. The resulting models and formulas provide for the design and analysis of forward signaling channels for wireless network systems.
Implementing a distributed fault-tolerant embedded system in Ada
Authors: Devesh Bhatt
Venue: Proceedings of the conference on TRI-ADA '90 (1990)

This paper presents the design and implementation experience of MEDS&mdash;an experimental distributed fault-tolerant system written in Ada that implements prototypes of some C3Ifunctions. MEDS implements distribution and fault-tolerance services such that application functions and data survive successive processor failures, and new or repaired processors can be added dynamically as additional resources. The design issues related to distribution/failure semantics, units of distribution, failure detection, reconfiguration, and recovery are discussed in the context of Ada. The design and implementation of these aspects of MEDS is presented and lessons learned from this experience are summarized.
Exploiting dead value information
Authors: Milo M. Martin, Amir Roth, Charles N. Fischer
Venue: Proceedings of the 30th annual ACM/IEEE international symposium on Microarchitecture (1997)

We describe Dead Value Information (DVI) and introduce three new optimizations which exploit it. DVI provides assertions that certain register values are dead, meaning they will not be read before being overwritten. The processor can use DVI to track dead registers and dynamically eliminate unnecessary save and restore instructions from the execution stream at procedure calls and context switches. Our results indicate that dynamic saves and restore instances can be reduced by 46% for procedure calls and by 51% for context switches. In addition, save/restore elimination for procedure calls can improve overall performance by up to 5%. DVI also allows the processor manage physical registers to efficiently, reducing the size requirements of the physical register file. When the system clock rate is proportional to the register file cycle time, this optimization can improve performance. All of these optimizations can be supported with only a few new instructions and minimal additional hardware structures.
Incremental analysis of real programming languages
Authors: Tim A. Wagner, Susan L. Graham
Venue: Proceedings of the ACM SIGPLAN 1997 conference on Programming language design and implementation (1997)

A major research goal for compilers and environments is the automatic derivation of tools from formal specifications. However, the formal model of the language is often inadequate; in particular, LR(k) grammars are unable to describe the natural syntax of many languages, such as C++ and Fortran, which are inherently non-deterministic. Designers of batch compilers work around such limitations by combining generated components with ad hoc techniques (for instance, performing partial type and scope analysis in tandem with parsing). Unfortunately, the complexity of incremental systems precludes the use of batch solutions. The inability to generate incremental tools for important languages inhibits the widespread use of language-rich interactive environments.We address this problem by extending the language model itself, introducing a program representation based on parse dags that is suitable for both batch and incremental analysis. Ambiguities unresolved by one stage are retained in this representation until further stages can complete the analysis, even if the reaolution depends on further actions by the user. Representing ambiguity explicitly increases the number and variety of languages that can be analyzed incrementally using existing methods.To create this representation, we have developed an efficient incremental parser for general context-free grammars. Our algorithm combines Tomita's generalized LR parser with reuse of entire subtrees via state-matching. Disambiguation can occur statically, during or after parsing, or during semantic analysis (using existing incremental techniques); program errors that preclude disambiguation retsin multiple interpretations indefinitely. Our representation and analyses gain efficiency by exploiting the local nature of ambiguities: for the SPEC95 C programs, the explicit representation of ambiguity requires only 0.5% additional space and less than 1% additional time during reconstruction.
An Algorithm Adapted Autonomous Controlling Concept for a Parallel Single-Chip Digital Signal Processor
Authors: Johannes Kneip, Mladen Berekovic, Jens Peter Wittenburg, Willm Hinrichs, Peter Pirsch
Venue: Journal of VLSI Signal Processing Systems (1997)

Recent sub-&mu; semiconductor technology supports the monolithic integration of multiprocessor systems. High wiring density and short on-chip memory access cycles motivate novel architecture concepts, outperforming conventional parallel systems. An efficient controlling strategy is a key to gain high performance from limited silicon resources. In this paper, a controlling concept for a monolithic Autonomous Single-Instruction/Multiple Data (ASIMD) processor is presented, which combines the high parallelism of an SIMD approach with the flexibility of standard DSP architectures. To demonstrate the performance gains of the concept, a digital video signal processor, the HiPAR-DSP has been implemented. It consists of an array of 4 or 16 datapaths, local memories for each datapath, a shared memory with concurrent data access in shape of a matrix and a central RISC controller. A three stage execution autonomy has been implemented, consisting of conditional instructions, conditional skip of instructions by the data paths and global evaluation of local conditions by the central controller. This allows efficient execution of data dependent medium- and high-level algorithms with very low controlling overhead. A performance of up to two arithmetic gigaoperations per second is achieved for algorithms with irregular data flow or control flow for the 100 MHz clocked processor with 16 data paths.
Fixpoint logics, relational machines, and computational complexity
Authors: Serge Abiteboul, Moshe Y. Vardi, Victor Vianu
Venue: Journal of the ACM (JACM) (1997)

We establish a general connection between fixpoint logic and complexity. On one side, we have fixpoint logic, parameterized by the choices of 1st-order operators (inflationary or noninflationary) and iteration constructs (deterministic, nondeterministic, or alternating). On the other side, we have the complexity classes between P and EXPTIME. Our parameterized fixpoint logics capture the complexity classes P, NP, PSPACE, and EXPTIME, but equally is achieved only over ordered structures. There is, however, an inherent mismatch between complexity and logic&mdash;while computational devices work on encodings of problems, logic is applied directly to the underlying mathematical structures. To overcome this mismatch, we use a theory of relational complexity, which bridges the gap between standard complexity and fixpoint logic. On one hand, we show that questions about containments among standard complexity classes can be translated to questions about containments among relational complexity classes. On the other hand, the expressive power of fixpoint logic can be precisely characterized in terms of relational complexity classes. This tight, three-way relationship among fixpoint logics, relational complexity and standard complexity yields in a uniform way logical analogs to all containments among the complexity classes P, NP, PSPACE, and EXPTIME. The logical formulation shows that some of the most tantalizing questions in complexity theory boil down to a single question: the relative power of inflationary vs. noninflationary 1st-order operators.
The Non-Optimality of the Monotonic Priority Assignmentsfor Hard Real-Time Offset Free Systems
Authors: J. Goossens, R. Devillers
Venue: Real-Time Systems (1997)

In this paper, we study the problem of scheduling hard real-time periodic tasks with static priority pre-emptive algorithms. We consider tasks which are characterized by a period, a hard deadline, a computation time and an offset (the time of the first request), where the offsets may be chosen by the scheduling algorithm, hence the denomination offset free systems. We study the rate monotonic and the deadline monotonic priority assignments for this kind of system and we compare the offset free systems and the asynchronous systems in terms of priority assignment. Hence, we show that the rate and the deadline monotonic priority assignments are not optimal for offset free systems.
Isoperimetric Inequalities and Eigenvalues
Authors: Nabil Kahale
Venue: SIAM Journal on Discrete Mathematics (1997)

An upper bound is given on the minimum distance between i subsets of same size of a regular graph in terms of the ith largest eigenvalue in absolute value. This yields a bound on the diameter in terms of the ith largest eigenvalue for any integer i. Our bounds are shown to be asymptotically tight for explicit families of graphs having an asymptotically optimal ith largest eigenvalue. A result by Quenell [Adv. Math., 106 (1994), pp. 122--148] relating the diameter, the second eigenvalue, and the girth of a regular graph is obtained as a by-product.
Implementing bit-addressing with specialization
Authors: Scott Draves
Venue: ACM SIGPLAN Notices (1997)

General media-processing programs are easily expressed with bit-addressing and variable-sized bit-fields. But the natural implementation of bit-addressing relies on dynamic shift offsets and repeated loads, resulting in slow execution. If the code is specialized to the alignment of the data against word boundaries, the offsets become static and many repeated loads can be removed. We show how introducing modular arithmetic into an automatic compiler generator enables the transformation of a program that uses bit-addressing into a synthesizes of fast specialized programs.In partiai-evaluation jargon we say: modular arithmetic is supported by extending the binding time lattice used by the static analysis in a polyvariant compiler generator. The new binding time Cyclic functions like a partially static integer.A software cache combined with a fast, optimistic sharing analysis built into the compilers eliminates repeated loads and stores. The utility of the transformation is demonstrated with a collection of examples and benchmark data. The examples include vector arithmetic, audio synthesis, image processing, and a base-64 codec.
On the runtime complexity of type-directed unboxing
Authors: Yasuhiko Minamide, Jacques Garrigue
Venue: Proceedings of the third ACM SIGPLAN international conference on Functional programming (1998)

Avoiding boxing when representing native objects is essential for the efficient compilation of any programming language For polymorphic languages this task is difficult, but several schemes have been proposed that remove boxing on the basis of type information. Leroy's type-directed unboxing transformation is one of them. One of its nicest properties is that it relies only on visible types, which makes it compatible with separate compilation. However it has been noticed that it is not safe both in terms of time and space complexity ---i.e. transforming a program may raise its complexity. We propose a refinement of this transformation, still relying only on visible types, and prove that it satisfies the safety condition for time complexity. The proof is an extension of the usual logical relation method, in which correctness and safety are proved simultaneously.
QoSMIC: quality of service sensitive multicast Internet protocol
Authors: Michalis Faloutsos, Anindo Banerjea, Rajesh Pankaj
Venue: ACM SIGCOMM Computer Communication Review (1998)

In this paper, we present, QoSMIC, a multicast protocol for the Internet that supports QoS-sensitive routing, and minimizes the importance of a priori configuration decisions (such as core selection). The protocol is resource-efficient, robust, flexible, and scalable. In addition, our protocol is provably loop-free.Our protocol starts with a resources-saving tree (Shared Tree) and individual receivers switch to a QoS-competitive tree (Source-Based Tree) when necessary. In both trees, the new destination is able to choose the most promising among several paths. An innovation is that we use dynamic routing information without relying on a link state exchange protocol to provide it. Our protocol limits the effect of pre-configuration decisions drastically, by separating the management from the data transfer functions; administrative routers are not necessarily part of the tree. This separation increases the robustness, and flexibility of the protocol. Furthermore, QoSMIC is able to adapt dynamically to the conditions of the network.The QoSMIC protocol introduces several new ideas that make it more flexible than other protocols proposed to date. In fact, many of the other protocols, (such as YAM, PIMSM, BGMP, CBT) can be seen as special cases of QoSMIC. This paper presents the motivation behind, and the design of QoSMIC, and provides both analytical and experimental results to support our claims.
An automatic and tunable document indexing system
Authors: Esen Ozkarahan, Fazli Can
Venue: Proceedings of the 9th annual international ACM SIGIR conference on Research and development in information retrieval (1986)

In this article we present an interactive automatic document indexing software together with various index tuning/optimization strategies. After stems are generated from the raw text, the initial index vocabulary is narrowed down and tuned with the use of indexing versus clustering theory relationships. The narrowed down vocabulary is further optimized with the inclusion of term phrases and virtual terms corresponding to high and low frequency terms respectively. The results of performance experimentation which proved significant improvements of index vocabulary optimization are presented. The exploitation of the term discrimination value concept in index and retrieval system tuning and optimization is discussed.
Extending the ODMG object model with composite objects
Authors: Elisa Bertino, Giovanna Guerrini
Venue: ACM SIGPLAN Notices (1998)

In this paper we extend the ODMG object data model with composite objects. A composite object is an object built by aggregating other component objects. Exclusiveness and dependency constraints, as well as referential integrity, can be associated with composition relationships among objects. Our composite object model is developed in the framework of the ODMG object database standard data model, but can be used in both object-oriented and object-relational database systems. In the paper, we propose a language for defining composite objects and we define the semantics of update operations on composite objects.
Computerized evaluation simulator based on the CIPP model
Authors: Takeshi Ohara, Kenneth Pickard
Venue: Proceedings of the 17th conference on Winter simulation (1985)

An attempt was made to build a computer simulation model based on an evaluation model. The model (CIPP) systematically examined each stage of evaluation activities (context, input, process, and product of a project). The administrators, funds, and program effectiveness were considered as major factors in a simulation model. An optimal solution approach was chosen to evaluate the simulation results. Jackson's time independent solution was used to calculate the solution. The purpose of this project was to construct an evaluation simulation model based on the CIPP model, so that the evaluator would be able to envisage the best-fit evaluation design using a given educational setting. The major factors were the characteristics of the students and the school, the preferential attitude of the administrators to a specific project and program, and the availability and capability of programs and funding agencies. This paper presents the methodology used in building the CIPP simulation. The study is composed of four sections: 1. A theoretical framework in which a systems analytical view of the CIPP model is presented. This includes descriptions and interactions of the functions within and between the components of CIPP model. 2. A system synthesis of the CIPP model in which the concept of probabilistic operations is implemented. 3. A theoretical presentation of the optimal solution of a simulation model which gives an estimation of what would be a good strategy an evaluator may adopt. 4. A summary of the results from the simulation experiment.
Image Compression Using KLT, Wavelets and an Adaptive Mixture of Principal Components Model
Authors: Nanda Kambhatla, Simon Haykin, Robert D. Dony
Venue: Journal of VLSI Signal Processing Systems (1998)

In this paper, we present preliminary results comparing the nature of the errors introduced by the mixture of principal components (MPC) model with a wavelet transform and the Karhunen Lo&egrave;ve transform (KLT) for the lossy compression of brain magnetic resonance (MR) images. MPC, wavelets and KLT were applied to image blocks in a block transform coding scheme. The MPC model partitions the space of image blocks into a set of disjoint classes and computes a separate KLT for each class. In our experiments, though both the wavelet transform and KLT obtained a higher peak signal to noise ratio (PSNR) than MPC, according to radiologists, MPC preserved the texture and boundaries of gray and white matter better than the wavelet transform or KLT.