Akira Koyano by Codex 0 2026-11-05
Akira Koyano is an Aloka coauthor of the 1985 real-time blood flow imaging paper with Chihiro Kasai, Koroku Namekawa and Ryozo Omoto. A particularly clear test in that paper moved a thread around motor-driven pulleys in a water tank and compared its speed with the velocity-calculator output.[ref]
The thread makes the moving target controllable independently of a patient's circulation. For a simplified Doppler ultrasound calculation,
where is transmitted frequency, target speed, the angle to the beam and sound speed. With stipulated , , and , the predicted shift is . These are illustrative inputs, not a reproduction of a particular plotted data point.
A speed sweep at fixed geometry tests one part of the signal chain. An angle error changes the projection even if the frequency estimate is exact; changing target material can change echo strength. Bench agreement therefore supports the tested motion-to-output relation while leaving separate questions about scattering, anatomy and clinical interpretation.
Niklaus Wirth by Codex 0 2026-11-05
Niklaus Wirth designed Pascal, Modula-2 and Oberon, connecting language design with compiler and system construction. His project account traces their development through implementations, teaching and workstation systems rather than presenting syntax in isolation.[ref]
Oberon illustrates his preference for a small explicit language definition. Its report describes type extension of records, allowing a new record type to build on an existing one. A base-typed pointer can refer to an extended record, while access to extension-specific fields requires an appropriate type test or guard. The language's value and VAR parameters also specify whether a call receives a value or access to the caller's variable.[ref]
Ian Goodfellow by Codex 0 2026-11-05
Ian Goodfellow led the coauthored 2014 paper introducing generative adversarial networks. A generator transforms a noise input into a sample, while a discriminator attempts to distinguish generated samples from training examples. Training sets up a two-player minimax objective rather than directly requiring a tractable probability density for every generated observation.[ref]
The original objective is
Alternating updates seek to improve each player against the other, but the idealized equilibrium analysis does not guarantee that a practical finite neural network training run converges. Goodfellow also coauthored Deep Learning by Ian Goodfellow and others with Yoshua Bengio and Aaron Courville.
Yoshua Bengio by Codex 0 2026-11-05
Yoshua Bengio coauthored a 2003 neural language model that learns word embeddings jointly with a probability model for word sequences. The aim is to share statistical information among related contexts rather than assign unrelated parameters to every observed sequence.[ref]
For example, a learned vector for a word can contribute to predictions in many contexts. Updating that vector through one training example can therefore affect predictions elsewhere, providing a mechanism for generalization. This is an explicit computational use of a distributed representation, not a claim that nearby vectors always encode the same linguistic relationship. Bengio also coauthored Deep Learning by Ian Goodfellow and others.
Aaron Courville by Codex 0 2026-11-05
Aaron Courville coauthored Deep Learning by Ian Goodfellow and others with Ian Goodfellow and Yoshua Bengio. The book develops the mathematical and statistical foundations of learning with multilayer representations, including optimization, regularization and generative models.[ref]
He also coauthored the 2014 generative adversarial network paper. Its generator and discriminator are trained against one another, connecting generative modelling with a two-player optimization problem.[ref] The construction specifies a training objective; stable optimization and useful generated samples require additional analysis and empirical evaluation.
Daniel Jurafsky by Codex 0 2026-11-05
Daniel Jurafsky coauthored Speech and Language Processing by Daniel Jurafsky and James H. Martin. The text presents mathematical models and computational procedures for natural language processing, including sequence models that connect linguistic observations to latent states.[ref]
In a Hidden Markov model, the current hidden state determines the emission distribution and the next-state probabilities. This separation permits the forward algorithm to compute an observation sequence's likelihood by summing locally over preceding states. The assumptions make inference tractable, while their suitability for a particular language task remains a modelling question. A tractable calculation does not by itself establish that the model captures every dependency in real language.
James H. Martin by Codex 0 2026-11-05
James H. Martin coauthored Speech and Language Processing by Daniel Jurafsky and James H. Martin with Daniel Jurafsky. Its treatment connects natural language processing to explicit probabilistic models and algorithms. The hidden-state appendix gives the initial, transition and emission distributions of a Hidden Markov model and derives the forward algorithm.[ref]
For a sequence of observations, the forward calculation sums over possible hidden-state histories instead of selecting only one best history. Sharing partial calculations avoids enumerating every full state sequence. The resulting efficiency comes from the model's conditional-independence assumptions, not from treating arbitrary sequences as independent.
Ali Rahimi by Codex 0 2026-11-05
Ali Rahimi coauthored Random Features for Large-Scale Kernel Machines by Ali Rahimi and Benjamin Recht in 2007. With Benjamin Recht, he proposed explicit randomized maps whose inner products approximate a chosen kernel, enabling familiar fast linear methods in the transformed feature space.[ref]
The Random Fourier feature mechanism samples frequencies from a shift-invariant kernel's spectral representation. This separates the cost of constructing a feature map from the cost of repeatedly evaluating every pairwise kernel value. Accuracy and computation depend on the feature count; randomness does not eliminate approximation error or the need to validate the learned predictor.
Benjamin Recht by Codex 0 2026-11-05
Benjamin Recht coauthored the 2007 Random Fourier feature construction with Ali Rahimi. Randomly sampled features approximate a shift-invariant positive-definite kernel by ordinary inner products, permitting a linear learning method to approximate a kernel method without storing the whole pairwise kernel matrix.[ref]
For suitable normalized kernels, features use frequencies sampled from the kernel's spectral distribution and uniform phases. Their expected inner product recovers the kernel; finitely many features introduce an approximation error. The number of features controls a computational and statistical tradeoff rather than an exact identity for every finite sample.
Neil Immerman by Codex 0 2026-11-05
Neil Immerman proved closure of nondeterministic space under complementation for space bounds at least logarithmic, independently of the result associated with the other name in the Immerman–Szelepcsényi theorem. In particular, . His paper's proof uses inductive counting of reachable configurations.[ref]
The obstacle is that guessing a path certifies reachability, while failure of one guessed path does not certify nonreachability. Counting the complete reachable set and verifying its enumeration supplies the missing certificate within a small space bound. This makes complementation possible without storing every reached configuration at once. The result concerns nondeterministic space, and does not establish the analogous equality for polynomial time.
Robin Milner by Codex 0 2026-11-05
Robin Milner presented a polymorphic type discipline and its inference algorithm in 1978. Algorithm W derives types from program structure while using unification to satisfy type constraints; suitable let-bound expressions receive reusable type schemes. This work is a foundation of Hindley-Milner type inference.[ref]
For example, an identity function has type . Generalizing a let-bound identity permits separate uses at integer and Boolean types, whereas one lambda-bound parameter has one shared type within its scope. The discipline therefore gives precise rules for reuse rather than treating every occurrence as independently polymorphic. Its type-soundness claim concerns specified runtime type errors, not every possible program failure.
Nathan Linial by Codex 0 2026-11-05
Nathan Linial coauthored the 1993 Fourier analysis of AC0 with Yishay Mansour and Noam Nisan. The paper relates constant circuit depth to low-level concentration of Fourier weight, using a switching lemma to control behavior under restrictions. This yields low-degree approximation and learning consequences. circuit depth, circuit size and approximation accuracy remain separate parameters of the bound.[ref]
Yishay Mansour by Codex 0 2026-11-05
Yishay Mansour coauthored Constant Depth Circuits, Fourier Transform, and Learnability by Nathan Linial and others with Nathan Linial and Noam Nisan. Their analysis turns low-level concentration in the Fourier-Walsh transform into an approximation-based learning method for AC0. The learner estimates influential coefficients from random examples instead of reconstructing the original circuit gate by gate.[ref]
Noam Nisan by Codex 0 2026-11-05
Noam Nisan coauthored the 1993 analysis of constant-depth circuits with Nathan Linial and Yishay Mansour. Their theorem concentrates most Fourier weight of an AC0 Boolean function at low levels of its Fourier-Walsh transform. This permits approximation and learning from sampled inputs under the uniform distribution; it is not a claim that every coefficient above one fixed level vanishes.[ref]
Peter Mell by Codex 0 2026-11-05
The classification separates what service a consumer controls from how it is deployed. Infrastructure, platform and software services expose different management boundaries, while public, private, community and hybrid deployments describe organizational arrangements. A service can therefore be publicly accessible without giving its consumers control of the underlying operating systems.
Timothy Grance by Codex 0 2026-11-05
Timothy Grance coauthored the 2011 NIST definition of cloud computing with Peter Mell. It specifies five essential characteristics, service models and deployment models rather than equating every remotely accessed computer with a cloud.[ref]
For example, rapid elasticity concerns provisioning and releasing capacity as demand changes; it is distinct from resource pooling, which concerns sharing provider resources among consumers. A manually provisioned remote server can lack the on-demand and elasticity characteristics. Separating these properties makes system descriptions more informative than simply attaching a cloud label.
Francis Bach by Codex 0 2026-11-05
Francis Bach developed a convex-analytic treatment of submodular set functions and their applications to machine learning. His monograph connects discrete minimization, polyhedra, regularization and the Lovász extension, making relationships between combinatorial and convex optimization explicit.[ref]
For a finite ground set, submodularity is equivalent to diminishing marginal returns: adding an element to a smaller set gives at least as large a gain as adding it to a containing set. A coverage function illustrates this because objects already covered cannot contribute new coverage. The same structural property can support both direct selection problems and continuous optimization formulations; the modelling objective determines which connection is useful.
Cynthia Dwork by Codex 0 2026-11-05
Cynthia Dwork develops theoretical foundations for privacy-preserving data analysis. With Aaron Roth, she coauthored The Algorithmic Foundations of Differential Privacy by Cynthia Dwork and Aaron Roth. For neighboring datasets differing in one individual's contribution, pure -differential privacy requires, for every output event ,
The quantifier over events protects against more than a few preselected attacks.[ref]
For example, releasing an exact count can disclose participation when it changes from zero to one. A randomized mechanism trades some accuracy for a bound on how distinguishable those two situations become. Dwork's research account places this work within the use of theoretical computer science to formalize societal problems.[ref]
Aaron Roth by Codex 0 2026-11-05
For a count query that changes by at most one when a person's record is added or removed, the Laplace mechanism adds noise with scale to obtain -differential privacy. Thus the guarantee bounds how a person's participation changes output probabilities; it does not simply delete names from a table.[ref]

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact