In recent times, image retrieval has garnered an increasing amount of interest due to the introduction of image datasets of significant size. Many methods have been suggested to retrieve images swiftly and accurately....
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ISBN:
(纸本)9781728170442
In recent times, image retrieval has garnered an increasing amount of interest due to the introduction of image datasets of significant size. Many methods have been suggested to retrieve images swiftly and accurately. However, the majority of these techniques are centered on the representation of the image. It is felt that alongside the representation of the image, smart storage is required that can rise to the demands of the task. A possible solution is to model human visual memory, retrieving images by imitating the brain's detection processes. This paper proposes a memory model that can be employed as smart memory for efficiently retrieving images based on image hashes. The memory model accepts hash code inputs derived from DWT and DCT transformations. The model is evaluated in terms of the memory capacity and the accuracy of the image retrieval. The results demonstrate that this model has a greater capacity and is significantly quicker than other types of memory models.
In human memory, impressive objects (those with attachments to strong emotions, such as happiness and sadness) are retained easily, while non-impressive objects (those without attachments to strong emotions) are not. ...
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ISBN:
(纸本)0964345692
In human memory, impressive objects (those with attachments to strong emotions, such as happiness and sadness) are retained easily, while non-impressive objects (those without attachments to strong emotions) are not. Furthermore, one can easily acquire systematic knowledge about a favorite field, while it is difficult to acquire such knowledge about a non-favorite field. Emotions thus seem to play an important role in retaining the memory of an object and in forming a conceptual memory of objects. We have therefore developed an emotion-memory model, and in this paper, we present a simulation result on concept forming.
This paper presents a task-centric memory model for 1000-core compute accelerators. Visual computing applications are emerging as an important class of workloads that can exploit 1000-core processors. hi these workloa...
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ISBN:
(纸本)9780769537719
This paper presents a task-centric memory model for 1000-core compute accelerators. Visual computing applications are emerging as an important class of workloads that can exploit 1000-core processors. hi these workloads, we observe data sharing and communication patterns that can be leveraged in the design of memory systems for,future 1000-core processors. Based on these insights, we propose a memory model that uses a software protocol, working in collaboration with hardware caches, to maintain a coherent, single-address space view of memory without the need for hardware coherence support. We evaluate the task-centric memory model in simulation on a 1024-core MIMD accelerator we are developing that, with the help of a runtime system, implements the proposed memory model. We evaluate coherence management policies related to the task-centric memory model and show that the overhead of maintaining a coherent view of memory in software can be minimal. We further show that, while software management may constrain speculative hardware prefetching into local caches, a common optimization, it does not constrain the more relevant use case of off-chip prefetching from DRAM into shared caches.
memory models define which executions of multithreaded programs are legal. This paper formalises in a fixpoint form the happens-before memory model, an over-approximation of the Java one, and it presents a static anal...
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ISBN:
(纸本)9783540791232
memory models define which executions of multithreaded programs are legal. This paper formalises in a fixpoint form the happens-before memory model, an over-approximation of the Java one, and it presents a static analysis using abstract interpretation. Our approach is completely independent of both the programming language and the analysed property. It also appears to be a promising framework to define, compare and statically analyse other memory models.
Weak memory models are a consequence of the desire on part of architects to preserve all the uniprocessor optimizations while building a shared memory multiprocessor. The efforts to formalize weak memory models of ARM...
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ISBN:
(纸本)9781538659847
Weak memory models are a consequence of the desire on part of architects to preserve all the uniprocessor optimizations while building a shared memory multiprocessor. The efforts to formalize weak memory models of ARM and POWER over the last decades are mostly empirical they try to capture empirically observed behaviors and end up providing no insight into the inherent nature of weak memory models. This paper takes a constructive approach to find a common base for weak memory models: we explore what a weak memory would look like if we constructed it with the explicit goal of preserving all the uniprocessor optimizations. We will disallow some optimizations which break a programmer's intuition in highly unexpected ways. The constructed model, which we call General Atomic memory model (GAM), allows all four load/store reorderings. We give the construction procedure of GAM, and provide insights which are used to define its operational and axiomatic semantics. Though no attempt is made to match GAM to any existing weak memory model, we show by simulation that GAM has comparable performance with other models. No deep knowledge of memory models is needed to read this paper.
Symbolic execution plays an important role in the area of software testing and program verification. However, there are several difficulties facing symbolic execution, one of which is how to abstract various data type...
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ISBN:
(纸本)9780769539300
Symbolic execution plays an important role in the area of software testing and program verification. However, there are several difficulties facing symbolic execution, one of which is how to abstract various data types in source codes. This paper addresses this problem by proposing a memory model that is based on the abstract symbol table. The abstract symbol table records names, abstract addresses and symbolic values of variables, which is a simple and accurate memory abstracting mechanism. The memory model is prerequisite for any technique involving symbolic execution, but this paper is the first one that systematically presents a memory model for symbolic execution that can handle various data types uniformly. Moreover, pointer arithmetic is supported, and the aliasing problem can be handled implicitly, so no extra alias algorithm is needed.
The knowledge of pointer behavior is very important for static analysis tools, especially the ones aiming at detecting C and related programming languages. But due to the usage of structure and the weakly typed featur...
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ISBN:
(纸本)9781479973774
The knowledge of pointer behavior is very important for static analysis tools, especially the ones aiming at detecting C and related programming languages. But due to the usage of structure and the weakly typed feature of C-like programming languages, obtaining such knowledge is not an easy work. In this paper, we present a modeling method based on 3-valued matrix. This model enables us to perform flow-sensitive points-to analysis to obtain the knowledge of pointer behavior. And specially, it relies on offsets instead of access paths to denote disjoint objects in the memory space, thereby addressing the issue mentioned just before. And moreover, the so-called 3-valued matrix is a compact representation of points-to sets. Such a representation is a key part for designating an effective flow-sensitive points-to analysis. We implement a prototype of our method, and give it an evaluation on a set of open source benchmarks. The experimental results prove the effectiveness of our method, and show that it is suitable for exploring large programs with reasonable accuracy.
Though traditional classification methods show well performance in classification tasks, most of them mainly lay emphasis on 'classification' rather than 'cognition'. When a new object that has never b...
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ISBN:
(纸本)9781728124858
Though traditional classification methods show well performance in classification tasks, most of them mainly lay emphasis on 'classification' rather than 'cognition'. When a new object that has never been seen is encountered, the traditional methods falsely default the image as a certain category that has been studied, however, humans can first identify the image as new. In this paper, we present a memory model for visual images classification based on residual neural network and Bayesian decision (VICRB). First, the feature vectors of the visual images for each category are extracted with residual neural network and each feature component may be correctly copied or randomly produced. Then the processes about how the visual images represent, store and retrieve are modeled. The feature vector of test images is matched with the feature vectors of learned images and the likelihood ratio is computed according to probabilistic inference theory. Finally, the odds value in favor of an old over a new image is computed by all likelihood values. According to the odd value, the Bayesian decision rule is applied to the image classification. Experimental results on two benchmark images datasets show that the presented memory model performs well in images classification tasks.
Given the complicated nature of modern shared memory systems, it is vital to have a systematic approach to specifying and analyzing memory consistency requirements. In this paper, we present the UMM specification fram...
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Given the complicated nature of modern shared memory systems, it is vital to have a systematic approach to specifying and analyzing memory consistency requirements. In this paper, we present the UMM specification framework, which integrates two key features to support memory model verification: (i) it employs a simple and generic memory abstraction that can capture a large collection of memory models as guarded commands with a uniform notation, and (ii) it provides built-in model checking capability to enable formal reasoning about thread behaviors. Using this framework, memory models can be specified in a parameterized style-designers can simply redefine a few-bypassing rules and visibility ordering rules to obtain an executable specification of another memory model. We formalize several classical memory models, including Sequential Consistency, Coherence, and PRAM, to illustrate the general techniques of applying this framework. We then provide an alternative specification of the Java memory model, based on a proposal from Manson and Pugh, and demonstrate how to analyze Java thread semantics using model checking. We also compare our operational specification style with axiomatic specification styles and explore a mechanism that converts a memory model definition from one style to the other. Copyright (c) 2005 John Wiley & Sons, Ltd.
Due to the fact that concurrent program's semantics can't be understood by relaxed memory model correctly, some unexpected faults, which are difficult to be detected, exist during its multi-threaded cross-exec...
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ISBN:
(纸本)9781467391047
Due to the fact that concurrent program's semantics can't be understood by relaxed memory model correctly, some unexpected faults, which are difficult to be detected, exist during its multi-threaded cross-execution. Therefore, this paper intends to establish an abstract memory model for concurrent program, conduct formal description of the memory access process that may exist in program memory access, and then utilize model checking technique to find out the common concurrent program error scenarios on this basis. We further design the semantic mutation operator, and investigate how to optimize the mutation process and how to generate mutants and test suite automatically. This study can set up a formal specification of concurrent program memory access semantics and provide a theoretical basis for other researches in the field of testing. It also serves as a basis to propose a semantic mutation testing technique oriented towards parallel program to assist parallel code testing in industry.
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