Processor speeds are improving faster than memory access speeds. The current generation of RISC processors can perform many two-dimensional graphics operations at or near memory or bus bandwidth speeds, rendering specialized hardware unnecessary for all but the most demanding applications. This paper describes the DECStation 3100 and DECStation 500/200CX color frame buffer hardware and several of the graphics algorithms used in the X server implementation. Measured performance numbers are presented ...
Tópico(s): Embedded Systems Design Techniques
1990 - Wiley | Software Practice and Experience
The results of expected performance analysis and simulation of three multiple processor Z-buffer architectures are presented. These architectures have been proposed as approaches to applying many processors, working in parallel, to the task of rapidly creating shaded raster images. These architectures are attractive since they offer potentially high performance, in terms of image update rate, at modest cost. All three approaches make use of multiple instances of identical processor modules. The ...
Tópico(s): Digital Image Processing Techniques
1980 - ACM SIGGRAPH | ACM SIGGRAPH Computer Graphics
Algorithms for adaptive, tapered quantization of color images are described. The research is motivated by the desire to display high-quality reproductions of color images with small frame buffers. It is demonstrated that many color images which would normally require a frame buffer having 15 bits per pixel can be quantized to 8 or fewer bits per pixel with little subjective degradation. In most cases, the resulting images look significantly better than those made with uniform quantization. The color ...
Tópico(s): Advanced Data Compression Techniques
1982 - ACM SIGGRAPH | ACM SIGGRAPH Computer Graphics
An approach to the analysis of overload control in a finite buffer is introduced in which the original queuing process is modeled by a birth-and-death (BD) or quasi-birth-and-death (QBD) process. Overload control means to adapt the input process or the service process during the time period when the buffer content exceeds a certain level until it drops to another level. Such a control is necessary to reduce the occurrence of system shutdown periods and to protect high-priority messages against low- ...
Tópico(s): Real-Time Systems Scheduling
1989 - IEEE Communications Society | IEEE Transactions on Communications
Chen and Williams [2] show how precomputed z-buffer images from different fixed viewing positions can be reprojected to produce an image for a new viewpoint. Here, images are precomputed for twigs and branches at various levels in the hierarchical structure of a tree, and adaptively combined depending on the position of the new viewpoint. The precomputed images contain multiple z levels to avoid missing pixels in the reconstruction, subpixel masks for antialiasing, and colors and normals for shading ...
Tópico(s): Remote Sensing and LiDAR Applications
1996 - Springer Vienna | Eurographics
Tópico(s): Speech Recognition and Synthesis
1952 - SAGE Publishing | Journal of Dental Research
Nine solutions to the cache consistency problem for shared-memory multiprocessors with multiple translation-lookaside buffers (TLBs) are described. A TLB's function is defined, and it is shown how TLB inconsistency arises in uniprocessor and multiprocessor architectures. The problem of TLB consistency is solved in a uniprocessor and in multiprocessors with a shared bus, virtual-address caches, and hardware cache consistency. Solutions that can be implemented in multiprocessors with more general interconnection ...
Tópico(s): Network Packet Processing and Optimization
1990 - IEEE Computer Society | Computer
This paper presents rendering techniques that use volumes as the basic geometric primitives. It defines data structures composed of numerous subvolumes, in excess of 100,000. Over each subvolume, a scalar field describes the variation of some physical quantity. The two rendering methods described herein assume a trilinear variation of this scalar field within each volume element, unlike voxel-based techniques that assume a constant value for each subvolume. The result is a higher order approximation ...
Tópico(s): Geological Modeling and Analysis
1988 - ACM SIGGRAPH | ACM SIGGRAPH Computer Graphics
In many segmentation processes, we assign new cases according to a model that was built on the basis of past cases. As long as the new cases are “similar enough” to the past cases, segmentation proceeds normally. However, when a new case is substantially different from the known cases, a reexamination of the previously created segments is required. The reexamination may result in the creation of new segments or in the updating of the existing ones. In this paper, we assume that in big and dynamic ...
Tópico(s): Time Series Analysis and Forecasting
2019 - Elsevier BV | Decision Support Systems
An improved buffer sizing method was proposed to deal with various uncertain problems in project management.Effects of project resource intensity,network structure complexity and managers' preference to risks on buffers were considered and integrated in this method,which ensured buffers sizing even more appropriate regardless of activities scale along chains.Moreover,buffer inherent significance was studied in depth,regarding practical circumstance of project and human subjective behavior,which ...
Tópico(s): Software Engineering Techniques and Practices
2008 - Elsevier BV | Computer Integrated Manufacturing Systems
Abstract We propose a new concept of a robust project schedule. The concept is based on the application of time buffers, whose length is known only to the project manager or even only to higher level decision makers, but not to the activity executors, so that the student syndrome does not influence the project realization to a too high extent. The buffers are inserted after each project activity and after each project stage. The role of the buffers is to ensure that delays in the execution of individual ...
Tópico(s): Construction Project Management and Performance
2014 - Elsevier BV | Procedia Computer Science
Abstract Shadow maps and shadow volumes are common techniques for computing real-time shadows. We optimize the performance of a hardware-accelerated shadow mapping algorithm by rasterizing the light frustum into the stencil buffer, in a manner similar to the shadow volume algorithm. The pixel shader code that performs shadow tests and illumination computations is applied only to the pixels that are inside the light frustum. We also use deferred shading to further limit the operations to visible ...
Tópico(s): Remote Sensing and LiDAR Applications
2003 - Taylor & Francis | Journal of Graphics Tools
Chip makers are designing a new generation of microprocessors to stop buffer overflow assaults, exploits that hackers often use to attack and extract data from PCs or servers. AMD's Athlon-64 chips for notebook and desktop computers and its Opteron processors for servers include features that provide buffer-overflow protection. Intel offers buffer-overflow protection in its Itanium chips for servers. A buffer overflow occurs when a program or process tries to store more data in a buffer than it ...
Tópico(s): Network Security and Intrusion Detection
2004 - IEEE Computer Society | Computer
Tópico(s): VLSI and Analog Circuit Testing
2015 - American Scientific Publishers | Journal of Medical Imaging and Health Informatics
Proposed compression system architecture based on Lempel-Ziv algorithm with sliding window history buffer, this architecture may be realized on FPGA, and can provide input data streams from multiple sources and context switching. Base requirements to impression system and compression system architecture were proposed. Compression system architecture should provide quick reconstruction possibility for building another system with other technical characteristics and architecture features (like reconfigurable ...
Tópico(s): Advanced Data Storage Technologies
2015 - Science and Information Organization | International Journal of Advanced Computer Science and Applications
Mahadev Satyanarayanan, Dileep Bhandarkar,
A major feature of the VAX-11 is its large virtual address space. This trace-driven simulation scheme evaluates address translation hardware that supports this feature cost-effectively.
Tópico(s): VLSI and Analog Circuit Testing
1981 - IEEE Computer Society | Computer
Methods for drawing sophisticated pictures of molecules on colour-raster graphics terminals are presented. These methods utilize depth buffers, which store, for each pixel, not only a colour and a shade, but also a z coordinate or depth. Depth buffers make it convenient to combine several different molecular representations into a single picture. The algorithms can produce cutaway views of protein interiors, cross-sections of proteinprotein interfaces, and translucent solvent-accessible surfaces ...
Tópico(s): Enzyme Structure and Function
1985 - Elsevier BV | Journal of Molecular Graphics
In this paper we propose two buffer circuits for footed domino logic circuit.It minimizes redundant switching at the output node.These circuits prevent propagation of precharge pulse to the output node during precharge phase which saves power consumption.Simulation is done using 0.18µm CMOS technology.We have calculated the power consumption, delay and power delay product of proposed circuits and compared the results with existing standard domino circuit for different logic function, loading condition, ...
Tópico(s): Parallel Computing and Optimization Techniques
2012 - | International Journal of VLSI Design & Communication Systems
Of the automatic-repeat-request (ARQ) techniques commonly used in communication systems, selective protocols, while the most efficient, have the notable drawback of requiring large buffers at the receiver side. A selective ARQ protocol with a finite-length buffer is described. If N is the number of codewords transmittable in the round-trip delay, the protocol requires a buffer length N+N/sub a/, N/sub a/>or=2 being an integer. A lower bound on the throughput of the protocol is derived. It achieves ...
Tópico(s): Coding theory and cryptography
1993 - IEEE Communications Society | IEEE Transactions on Communications
An ion in a radio frequency ion trap interacting with a buffer gas of ultracold neutral atoms is a driven dynamical system which has been found to develop a nonthermal energy distribution with a power law tail. The exact analytical form of this distribution is unknown, but has often been represented empirically by q-exponential (Tsallis) functions. Based on the concepts of superstatistics, we introduce a framework for the statistical mechanics of an ion trapped in an rf field subject to collisions ...
Tópico(s): Gaussian Processes and Bayesian Inference
2017 - American Physical Society | Physical Review Letters
Marie‐Josèphe Tainturier, Brenda Rapp,
Background: The graphemic buffer was originally conceived as a component dedicated to the temporary storage of abstract orthographic representations prior to their format-specific expression in spelling (Caramazza, Miceli, Villa, & Romani, 1987). Since then, it has been argued that the graphemic buffer is also involved in reading (Caramazza, Capasso, & Miceli, 1996). Aims: The goal of this study was to test the hypothesis that a single graphemic buffer is used in reading and spelling. In addition, we ...
Tópico(s): Text Readability and Simplification
2003 - Taylor & Francis | Aphasiology
И. А. Дудина, Andrey Belevantsev,
Tópico(s): Software Testing and Debugging Techniques
2017 - Pleiades Publishing | Programming and Computer Software
Zhao Zhang, Zhichun Zhu, Xiaodong Zhang,
Tópico(s): Advanced Memory and Neural Computing
2001 - | The journal of instruction-level parallelism
Krerk Piromsopa, Richard Enbody,
Buffer-overflow attacks began two decades ago and persist today.Over that time, a number of researchers have proposed many solutions.Their targets were either to prevent or to protect against buffer-overflow attacks.As defenses improved, attacks adapted and became more complicated.Given the maturity of field and the fact that some solutions now exist that can prevent most buffer-overflow attacks, it is time to examine these schemes and their critical issues.In this survey, approaches were categorized ...
Tópico(s): Advanced Malware Detection Techniques
2011 - Chulalongkorn University | Engineering Journal
Richard Brice, Stephen W. Sherman,
Buffer pools are created and managed in database systems in order to reduce the total number of accesses to the I/O devices. In systems using virtual memory, any reduction in I/O accesses may be accompanied by an increase in paging. The effects of these factors on system performance are quantified, where system performance is a function of page faults and database accesses to the I/O devices. A previous study of this phenomenon is extended through the analysis of empirical data gathered in a multifactor ...
Tópico(s): Advanced Data Storage Technologies
1977 - Association for Computing Machinery | ACM Transactions on Database Systems
A virtual-address translation buffer (TB) is a hardware cache of recently used virtual-to-physical address mappings. The authors present the results of a set of measurements and simulations of translation buffer performance in the VAX-11/780. Two different hardware monitors were attached to VAX-11/780 computers, and translation buffer behavior was measured. Measurements were made under normal time-sharing use and while running reproducible synthetic time-sharing work loads. Reported measurements ...
Tópico(s): Embedded Systems Design Techniques
1985 - Association for Computing Machinery | ACM Transactions on Computer Systems
A discrete-time buffer with one single output channel, synchronous transmission of messages and an infinite waiting room is considered, where the output line is subjected to random interruptions in time. The stochastic nature of the interruption process is described by two independents sets of i.i.d. random variables: 'available periods', during which the output line is available for the transmission of data from the buffer, and 'blocked periods', during which it is not. It is shown how expressions ...
Tópico(s): Real-Time Systems Scheduling
1986 - Elsevier BV | European Journal of Operational Research
Krerk Piromsopa, Richard Enbody,
We propose a minimalist, architectural approach, Secure Bit (patent pending), to protect against buffer overflow attacks on control data (return-address and function-pointer attacks in particular). Secure Bit provides a hardware bit to protect the integrity of addresses for the purpose of preventing such buffer-overflow attacks. Secure Bit is transparent to user software: it provides backward compatibility with legacy user code. It can detect and prevent all address-corrupting buffer-overflow attacks ...
Tópico(s): Network Security and Intrusion Detection
2006 - IEEE Computer Society | IEEE Transactions on Dependable and Secure Computing
In this paper we develop a technique for transforming an internal-memory tree data structure into an external-memory structure. We show how the technique can be used to develop a search tree like structure, a priority queue, a (one-dimensional) range tree and a segment tree, and give examples of how these structures can be used to develop efficient I/O algorithms. All our algorithms are either extremely simple or straightforward generalizations of known internal-memory algorithms - given the developed ...
Tópico(s): Advanced Database Systems and Queries
1996 - | BRICS Report Series
Xuanping Zhang, Zhongmeng Zhao, Jiayin Wang,
A new image encryption algorithm based on spatiotemporal chaotic system is proposed, in which the circular S-box and the key stream buffer are introduced to increase the security. This algorithm is comprised of a substitution process and a diffusion process. In the substitution process, the S-box is considered as a circular sequence with a head pointer, and each image pixel is replaced with an element of S-box according to both the pixel value and the head pointer, while the head pointer varies ...
Tópico(s): Cellular Automata and Applications
2014 - Elsevier BV | Signal Processing Image Communication