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Memory Model (other)
Memory model may refer to: Psychology *Atkinson–Shiffrin memory model *Baddeley's model of working memory * Memory-prediction model Computer science * Memory model (programming) describes how threads interact through memory ** Java Memory Model ** Consistency model * Memory model (addressing scheme), an addressing scheme for computer memory address space ** Flat memory model ** Paged memory model ** Segmented memory Memory segmentation is an operating system memory management technique of division of a computer's primary memory into segments or sections. In a computer system using segmentation, a reference to a memory location includes a value that identifi ... ** One of the x86 memory models {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atkinson–Shiffrin Memory Model
The Atkinson–Shiffrin model (also known as the multi-store model or modal model) is a model of memory proposed in 1968 by Richard Atkinson and Richard Shiffrin. The model asserts that human memory has three separate components: # a '' sensory register'', where sensory information enters memory, # a '' short-term store'', also called ''working memory'' or ''short-term memory'', which receives and holds input from both the sensory register and the long-term store, and # a '' long-term store'', where information which has been rehearsed (explained below) in the short-term store is held indefinitely. Since its first publication, this model has come under much scrutiny and has been criticized for various reasons (described below). However, it is notable for the significant influence it had in stimulating subsequent memory research. Summary The model of memories is an explanation of how memory processes work. The three-part, multi-store model was first described by Atkinson and Sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baddeley's Model Of Working Memory
Baddeley's model of working memory is a model of human memory proposed by Alan Baddeley and Graham Hitch in 1974, in an attempt to present a more accurate model of primary memory (often referred to as short-term memory). Working memory splits primary memory into multiple components, rather than considering it to be a single, unified construct. Baddeley & Hitch proposed their three-part working memory model as an alternative to the short-term store in Atkinson & Shiffrin's 'multi-store' memory model (1968). This model is later expanded upon by Baddeley and other co-workers to add a fourth component, and has become the dominant view in the field of working memory. However, alternative models are developing, providing a different perspective on the working memory system. The original model of Baddeley & Hitch was composed of three main components: the ''central executive'' which acts as a supervisory system and controls the flow of information from and to its ''slave systems'': the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory-prediction Model
The memory-prediction framework is a theory of brain function created by Jeff Hawkins and described in his 2004 book ''On Intelligence''. This theory concerns the role of the mammalian neocortex and its associations with the hippocampi and the thalamus in matching sensory inputs to stored memory patterns and how this process leads to predictions of what will happen in the future. Overview The theory is motivated by the observed similarities between the brain structures (especially neocortical tissue) that are used for a wide range of behaviours available to mammals. The theory posits that the remarkably uniform ''physical'' arrangement of cortical tissue reflects a single principle or algorithm which underlies all cortical information processing. The basic processing principle is hypothesized to be a feedback/recall loop which involves both cortical and extra-cortical participation (the latter from the thalamus and the hippocampi in particular). The basic theory: recognitio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Model (programming)
In computing, a memory model describes the interactions of Thread (computer science), threads through memory (computing), memory and their shared use of the data (computing), data. History and significance A memory model allows a compiler to perform many important optimizations. Compiler optimizations like loop fusion move statements in the program, which can influence the order of read and write operations of potentially shared variable (programming), variables. Changes in the ordering of reads and writes can cause race conditions. Without a memory model, a compiler is not allowed to apply such optimizations to multi-threaded programs in general, or only in special cases. Or for some compilers assume no multi-threaded execution (so better optimized code can be produced), which can lead to optimizations that are incompatible with multi-threading - these can often lead to subtle bugs, that don't show up in early testing. Modern programming languages like Java (programming language) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consistency Model
In computer science, a consistency model specifies a contract between the programmer and a system, wherein the system guarantees that if the programmer follows the rules for operations on memory, memory will be consistent and the results of reading, writing, or updating memory will be predictable. Consistency models are used in distributed systems like distributed shared memory systems or distributed data stores (such as filesystems, databases, optimistic replication systems or web caching). Consistency is different from coherence, which occurs in systems that are cached or cache-less, and is consistency of data with respect to all processors. Coherence deals with maintaining a global order in which writes to a single location or single variable are seen by all processors. Consistency deals with the ordering of operations to multiple locations with respect to all processors. High level languages, such as C++ and Java, maintain the consistency contract by translating memory operat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Model (addressing Scheme)
In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware. Memory addresses are fixed-length sequences of digits conventionally displayed and manipulated as unsigned integers. Such numerical semantic bases itself upon features of CPU (such as the instruction pointer and incremental address registers), as well upon use of the memory like an array endorsed by various programming languages. Types Physical addresses A digital computer's main memory consists of many memory locations. Each memory location has a physical address which is a code. The CPU (or other device) can use the code to access the corresponding memory location. Generally only system software, i.e. the BIOS, operating systems, and some specialized utility programs (e.g., memory testers), address physical memory using machine code operands or processor registers, instructing the CPU to direct a hardware device, called the memory controller, to use the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flat Memory Model
Flat memory model or linear memory model refers to a memory addressing paradigm in which "memory appears to the program as a single contiguous address space." The CPU can directly (and linearly) address all of the available memory locations without having to resort to any sort of memory segmentation or paging schemes. Memory management and address translation can still be implemented ''on top of'' a flat memory model in order to facilitate the operating system's functionality, resource protection, multitasking or to increase the memory capacity beyond the limits imposed by the processor's physical address space, but the key feature of a flat memory model is that the entire memory space is linear, sequential and contiguous. In a simple controller, or in a ''single tasking'' embedded application, where memory management is not needed nor desirable, the flat memory model is the most appropriate, because it provides the simplest interface from the programmer's point of view, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paged Memory
In computer operating systems, memory paging is a memory management scheme by which a computer stores and retrieves data from secondary storage for use in main memory. In this scheme, the operating system retrieves data from secondary storage in same-size blocks called ''pages''. Paging is an important part of virtual memory implementations in modern operating systems, using secondary storage to let programs exceed the size of available physical memory. For simplicity, main memory is called "RAM" (an acronym of random-access memory) and secondary storage is called "disk" (a shorthand for hard disk drive, drum memory or solid-state drive, etc.), but as with many aspects of computing, the concepts are independent of the technology used. Depending on the memory model, paged memory functionality is usually hardwired into a CPU/MCU by using a Memory Management Unit (MMU) or Memory Protection Unit (MPU) and separately enabled by privileged system code in the operating system's ker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segmented Memory
Memory segmentation is an operating system memory management technique of division of a computer's primary memory into segments or sections. In a computer system using segmentation, a reference to a memory location includes a value that identifies a segment and an offset (memory location) within that segment. Segments or sections are also used in object files of compiled programs when they are linked together into a program image and when the image is loaded into memory. Segments usually correspond to natural divisions of a program such as individual routines or data tables so segmentation is generally more visible to the programmer than paging alone. Segments may be created for program modules, or for classes of memory usage such as code and data segments. Certain segments may be shared between programs. Segmentation was originally invented as a method by which system software could isolate software processes ( tasks) and data they are using. It was intended to increase re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
