Felix A. Gers 2026-11-05
Felix A. Gers is a researcher in machine learning and recurrent neural networks. His institutional profile connects his research with long short-term memory; the full-name byline of his2000paper verifies the name used here.[ref] [ref]
Learning to Forget: Continual Prediction with LSTM by Felix A. Gers, Jürgen Schmidhuber and Fred Cummins. MIT Press full author byline; DOI10.1162/089976600300015015
With Jürgen Schmidhuber and Fred Cummins, he introduced the adaptive LSTM forget gate to address continual input streams lacking externally marked reset points. The gate lets a LSTM memory cell learn when to reduce retained state, rather than requiring every sequence boundary to be supplied from outside.[ref]
Learning to Forget: Continual Prediction with LSTM by Felix A. Gers, Jürgen Schmidhuber and Fred Cummins. Abstract: continual prediction and learned resets
A scalar toy update makes selective retention tangible:Here is a retention multiplier and a new contribution. With and , choices , and retain , and respectively. This arithmetic illustrates one role of a LSTM forget gate; it omits the other gates and training equations of a complete long short-term memory network. Forgetting stored state is also distinct from discarding all learned network parameters.
Felix Gers, identified on his BHT research profile
. External institutional portrait from Felix Gers profile by BHT. Forget gate in long short-term memory 2026-11-05
The forget gate in long short-term memory controls retention of the previous memory state in a long short-term memory recurrent neural network. In a simplified modern update,Each component of multiplies the corresponding old memory component. Values near one retain it strongly; values near zero suppress it. The input gate in long short-term memory controls the separate new-write term.[ref]
LSTM: A Search Space Odyssey by Klaus Greff and others. Section II and Figure 1; simplified form here omits peepholes.
If a scalar gate stays at and the new-write term is zero, then after steps . The half-retention time isThis gives an interpretable timescale for a learned multiplicative gate. An exact no-write term is an illustrative condition; finite logistic sigmoid function outputs are strictly between zero and one, though the candidate can itself be zero.
The forget gate was added after the 1997 architecture. Felix A. Gers, Jürgen Schmidhuber and Fred Cummins introduced adaptive forgetting to handle continuing streams where a memory needs to be reset rather than preserved indefinitely. The direct memory-path derivative contains products of forget gates; the full recurrent derivative also includes dependencies through other states and gates.[ref]
Learning to Forget: Continual Prediction with LSTM by Felix A. Gers, Jürgen Schmidhuber and Fred Cummins. Abstract and adaptive forget-gate motivation for continual prediction.
Fred Cummins 2026-11-05
Fred Cummins is a researcher in cognitive science and speech whose work includes the timing of people speaking together. A2019speaker profile describes his empirical investigation of joint speech. His own publication list also confirms coauthorship of the2000long short-term memory forget-gate paper with Felix A. Gers and Jürgen Schmidhuber.[ref]
Fred Cummins speaker profile at Battle of Ideas 2019. Date-specific speaker biography and author publication-list cross-check
His2003study of synchronous speech asked pairs of readers to speak a prepared text together and measured their timing. Across the reported conditions, corresponding points were typically separated by about40milliseconds, with larger differences at phrase beginnings. Comparison conditions examined practice and visual access to the partner; both speakers adjusted their timing relative to individual control readings.[ref]
Practice and performance in speech produced synchronously by Fred Cummins. Abstract; Methods; synchrony and phrasal-position results
This supplies a concrete scientific question: is coordinated timing produced by one speaker simply trailing the other, or by mutual adjustment? Recording both voices and comparing them with individual readings can distinguish these accounts. The result concerns a structured reading task, rather than proving that every spontaneous crowd utterance follows the same timing rule.
Fred Cummins, identified on his2019speaker profile
. External portrait from Fred Cummins speaker profile at Battle of Ideas 2019. Input gate in long short-term memory 2026-11-05
The input gate in long short-term memory controls how much proposed new information is written into the memory state of a long short-term memory recurrent neural network. In a common modern form,Here is the candidate memory update, is the input-gate vector, and means componentwise multiplication. The sigmoid function places each gate component between zero and one. The forget gate in long short-term memory separately controls the existing memory: suppressing a new write does not by itself erase stored information.[ref]
LSTM: A Search Space Odyssey by Klaus Greff and others. Section II, Figure 1: memory update and input-gate role; equations here omit peephole connections.
For a scalar example, let , , and . Then . Increasing only to gives : a larger gate admits more of the negative candidate. The gate is a multiplier, not an instruction that the memory must increase.
The proposed write and its admission are learned separately. An input may suggest a strong candidate while the gate learns that this timestep should be ignored. This selective writing was part of the original memory-cell strategy for protecting information across long delays, together with gated reading through the output gate in long short-term memory.[ref]
Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Memory-cell construction and input/output gates protecting constant error flow.
Jürgen Schmidhuber 2026-11-05
Jürgen Schmidhuber is a computer scientist whose research includes learning architectures for recurrent neural networks. He coauthored the1997long short-term memory paper with Sepp Hochreiter and the2000adaptive-forgetting paper with Felix A. Gers and Fred Cummins. These are team contributions documented by the original bylines.[ref] [ref] [ref]
The1997architecture separates a persistent internal state from learned control of access to that state. A LSTM input gate controls new input, while a LSTM output gate controls how stored information influences output. This arrangement was designed to reduce the vanishing gradient problem that makes distant events difficult to associate during learning.[ref]
Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Abstract; Sections3–4: constant error flow and multiplicative gates
An illustrative task presents a marked value early in a long stream, then asks for it after many irrelevant inputs. A network needs both a way to retain the relevant information and a way to protect it from later interference. The paper tested artificial long-delay tasks; success on those experiments is evidence about the architecture and learning procedure under specified conditions, not a guarantee of unlimited or error-free memory.
Jürgen Schmidhuber, photograph linked from his author homepage
. External photograph identified in the Photos list of Jürgen Schmidhuber homepage. Klaus Greff 2026-11-05
Klaus Greff is a machine learning researcher whose work includes controlled comparisons of long short-term memory architectures. His author homepage identifies the researcher and links his publications; the original byline of LSTM: A Search Space Odyssey by Klaus Greff and others confirms his participation in that study.[ref]
The study compared eight architectural variants across three task families, optimizing hyperparameters separately for each variant. This matters because a poorly tuned variant is not a fair test of its architecture. None significantly improved on the standard architecture in the reported comparisons, while removing particular components exposed the importance of the LSTM forget gate and output activation.[ref]
LSTM: A Search Space Odyssey by Klaus Greff and others. Abstract: variant comparisons, separate tuning and component importance
For an illustrative ablation study, compare a complete recurrent neural network with a version lacking one gate, while keeping the training task and evaluation procedure comparable. A worse result after removal is evidence about that component under the tested conditions; it does not establish that no alternative architecture could ever replace it. This is the scientific value of a controlled comparison beyond displaying one successful network.
Klaus Greff, identified on his author homepage
. External portrait linked and labeled by Klaus Greff homepage. LSTM memory cell 2026-11-05
An LSTM memory cell is the state-carrying unit of a long short-term memory recurrent neural network. It maintains an internal memory whose update is controlled by gates, while an exposed state communicates selected information to the rest of the network. The memory and exposed output are different quantities.[ref]
Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Memory-cell construction and gated access to persistent state.
In a simplified modern form, omitting peepholes,The LSTM forget gate regulates retention, the LSTM input gate regulates the candidate write , and the LSTM output gate regulates exposure. The componentwise product allows different memory coordinates to make different decisions.[ref]
LSTM: A Search Space Odyssey by Klaus Greff and others. Section II and Figure 1; the displayed simplified variant omits the baseline's peephole connections.
For a scalar example, , , and give . If , the output is only . A small output can coexist with substantial stored state; it does not demonstrate memory erasure.
The additive state path was designed to help learning across long delays. The original 1997 architecture had input/output gating; adaptive forgetting was introduced later for continuing streams. Preserving a direct gradient path addresses an important learning difficulty but does not guarantee unlimited or perfectly reliable memory for every task.[ref]
Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Constant error flow and delayed-dependency experiments.
[ref]Learning to Forget: Continual Prediction with LSTM by Felix A. Gers, Jürgen Schmidhuber and Fred Cummins. Adaptive forget gate and continual prediction.
Output gate in long short-term memory 2026-11-05
The output gate in long short-term memory controls how much stored memory is exposed as the recurrent output of a long short-term memory network. In a common form,The memory is , the exposed state is , is a logistic sigmoid function, and is the hyperbolic tangent. The output gate in long short-term memory modulates the exposed state rather than directly multiplying the stored memory itself.[ref]
LSTM: A Search Space Odyssey by Klaus Greff and others. Section II, Figure 1: output activation and gate; simplified no-peephole equations.
For example, if , then . An output gate yields , whereas yields . Both cases can have the same current memory. A small exposed value therefore does not establish that the internal memory has been erased.
Selective exposure lets a network retain information until it becomes useful for a later prediction. The original architecture combined output gating with an input gate in long short-term memory to regulate access to persistent memory. Changing the exposed state may affect later gate decisions, so “does not directly erase” does not mean the output gate has no influence on future memory evolution.[ref]
Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Memory-cell input/output gates and long-delay learning motivation.
Sepp Hochreiter 2026-11-05
Sepp Hochreiter is a computer scientist working on machine learning and neural networks. His institutional profile identifies long short-term memory among his research topics. The1997paper with Jürgen Schmidhuber connects his earlier analysis of decaying learning signals to a recurrent architecture designed to preserve useful error flow.[ref]
Sepp Hochreiter profile by JKU. Institutional identification and research topics
[ref]Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Abstract; Section3 and its account of the1991analysis
A toy chain rule calculation explains the motivation. If a learning signal is multiplied by at each of twenty successive steps, its contribution is scaled byThat small contribution can make an early input difficult to associate with a much later training signal. The example illustrates the vanishing gradient problem; it is not a measurement of every recurrent neural network.
The long short-term memory design introduced a controlled internal path with constant error flow, while multiplicative gates regulate access. Its artificial-data experiments included successful learning across delays exceeding1000discrete steps. The reported capability belongs to those experiments and their architecture-specific learning rules, rather than implying that any trained instance will remember every input indefinitely.[ref]
Long Short-Term Memory by Sepp Hochreiter and Jürgen Schmidhuber. Abstract; Sections3–5: error-flow construction and artificial tasks
Sepp Hochreiter, identified on his JKU institutional profile
. External institutional portrait from Sepp Hochreiter profile by JKU. Tesseract (software) 2026-11-05
Tesseract is an open-source engine for optical character recognition. It combines image analysis with trained recognition data to extract text from images. Its documentation describes a command-line interface and a programming interface, with recognition data for different writing systems. A language choice affects the model used; it does not translate the recognized text.[ref]
Tesseract User Manual by the Tesseract project. Introduction and Usage; Command Line Usage, Using One Language
For example, the documented command
tesseract scan.png result -l eng reads an image, selects English recognition data and writes text to result.txt. The output basename is result, so the filename extension is supplied by the selected output format. Adding pdf requests a PDF containing the page image and a searchable text layer. If recognition confuses a letter in the image, searching that text layer can still miss the intended word.[ref]Tesseract User Manual by the Tesseract project. Command Line Usage, Simplest Invocation, Using One Language and Searchable pdf output
The architecture has changed over its history. Ray Smith's 2007 paper describes an engine that groups connected image outlines into lines and words, then recognizes them in successive passes. Version 4 introduced recognition based on long short-term memory neural networks; the 5.x manual documents this engine alongside the legacy option.[ref]
An Overview of the Tesseract OCR Engine by Ray Smith. §2, printed p. 629, architecture and recognition passes
[ref]Tesseract User Manual by the Tesseract project. Tesseract with LSTM; Command Line Usage, Available OCR Engines in Tesseract 5
A useful test compares output with a checked transcription using character error rate, while also inspecting omitted regions and reading order. Recognition accuracy depends on image quality, layout and matching language data. Installing the engine alone does not establish the accuracy of a particular scanned collection.




