A Fire Upon the Deep is a 1992 science fiction novel by American writer Vernor Vinge. It is a space opera involving superhuman intelligences, aliens, variable physics, space battles, love, betrayal, genocide, and a communication medium resembling Usenet. A Fire Upon the Deep won the Hugo Award in 1993, sharing it with Doomsday Book by Connie Willis. Besides the normal print book editions, the novel was also included on a CD-ROM sold by ClariNet Communications along with the other nominees for the 1993 Hugo awards. The CD-ROM edition included numerous annotations by Vinge on his thoughts and intentions about different parts of the book, and was later released as a standalone e-book. It has a loose prequel, A Deepness in the Sky, from 1999, and a direct sequel, The Children of the Sky, from 2012. == Setting == The novel is set in various locations within the Milky Way. The galaxy is divided into four concentric volumes called the "Zones of Thought"; it is not clear to the novel's characters whether this is a natural phenomenon or an artificially created one. Each Zone has fundamental differences in basic physical laws. One of the main consequences of these differences is the effect on intelligence. Artificial intelligence and automation is most directly affected, in that advanced hardware and software from the Beyond or the Transcend will work less and less well as a ship descends towards the Unthinking Depths. Biological intelligence is affected to a lesser degree. The four zones are spoken of in terms of "low" to "high" as follows: The Unthinking Depths are the innermost zone, surrounding the Galactic Center. In it, only minimal forms of intelligence, biological or otherwise, are possible. This means that any ship straying into the Depths will be stranded, effectively permanently. Even if the crew did not die immediately—and some forms of life native to "higher" Zones would likely do so—they would be rendered incapable of even human intelligence, leaving them unable to operate their ship in any meaningful way. Surrounding the Depths is the Slow Zone or Slowness. "Old Earth" is in this Zone, although Earth plays no significant role in the story. Biological intelligence is possible in "the Slowness", but not true, sentient, artificial intelligence. Faster than light travel (FTL) is impossible in the Slow Zone. Faster-than-light communication is impossible into or out of the Slow Zone. As the boundaries of the Zones are subject to change, accidental entry into the Slow Zone is a major hazard at the "Bottom" of the Beyond. Starships which operate near the Beyond/Slow Zone border often have an auxiliary Bussard ramjet drive, so that if they accidentally stray into the Slow Zone, they will at least have a backup (sub-light) drive to try to reach the Beyond. Such ships also tend to include "coldsleep" equipment, as it is likely that any such return will still take many lifetimes for most species. The next layer outward is the Beyond, within which artificial intelligence, FTL travel, and FTL communication are possible. All human civilizations in the Beyond are descended from a single ethnic Norwegian group. The original settlement of this group is known as Nyjora; other human settlements in the Beyond include Straumli Realm and Sjandra Kei. In the Beyond, FTL travel is accomplished by making many small "jumps" across space, with the efficiency of the drive increasing the farther a ship travels from the galactic core. The Beyond is not a homogeneous zone; it includes the "High Beyond", "Middle Beyond", and the "Bottom of the Beyond", depending on distance from the galactic core. The Beyond is populated by a very large number of interstellar and intergalactic civilizations which are linked by an FTL communication network, "the Net", sometimes cynically called the "Net of a Million Lies". The Net is depicted as working much like the Usenet network in the early 1990s, with transcripts of messages containing header and footer information as one would find in such forums. The outermost layer, containing the galactic halo, is the Transcend, within which incomprehensible, superintelligent beings dwell. When a "Beyonder" civilization reaches the point of technological singularity, it can "Transcend", becoming a "Power". Such Powers always seem to relocate to the Transcend, seemingly necessarily, where they become engaged in activities which are entirely mysterious to those in the Beyond. == Plot == An expedition from Straumli Realm, a human civilization in the High Beyond, investigates a newly discovered data archive in the Low Transcend. The expedition's facility, High Lab, is gradually compromised by a superintelligence that is accidentally awoken by the researchers. This superintelligence is later known as the Blight. Shortly before the Blight's final "flowering", two self-aware entities, created similarly to the Blight, plot to aid the humans before the Blight can gain its full powers. Finally recognizing their danger, the High Lab researchers attempt to flee in two ships. The Blight destroys one ship; a second ship, carrying many High Lab children in coldsleep boxes, escapes. This ship lands on a distant planet at the Bottom of the Beyond. The planet is occupied by dog-like creatures, dubbed "Tines", who live in packs as group minds. The Tines have a level of technology comparable to the human Middle Ages. Upon landing, however, the two surviving adults, Arne and Sjana Olnsdot, are ambushed and killed by Tine fanatics known as Flenserists, in whose realm they have landed. The Flenserists capture their children, Jefri and Johanna. Johanna is rescued by a Tine named Peregrine and taken to a neighboring kingdom ruled by Woodcarver. A distress signal from the Straumli ship eventually reaches Relay, a major information provider for the Net. A Transcendent being named "Old One" contacts Relay, seeking information about the Blight and the humans who released it. Old One then reconstitutes a human man named Pham Nuwen from the wreckage of a spaceship to act as its agent. Pham remains unsure if he is a construct or if his memories are real. Ravna Bergsndot, the only human Relay employee, traces the Straumli ship's signal to the Tines' world and persuades her employer to investigate. Ravna contracts the merchant vessel Out of Band II to transport her and Pham. The ship is owned by two Skroderiders, Blueshell and Greenstalk. Before the mission is launched, the Blight launches a surprise attack on Relay and kills Old One. As Old One dies, it downloads its anti-Blight information into Pham. Pham, Ravna and the Skroderiders barely escape Relay's destruction in the Out of Band II. During their journey to Tine's World, Ravna communicates with Jefri. Jefri is manipulated to believe that Woodcarver is his enemy. The Flenserist leaders, Steel and Tyrathect, use Ravna's information to develop advanced technology such as cannon and radio communication. Meanwhile, Johanna and the knowledge stored in her dataset device help Woodcarver rapidly develop as well. The Blight expands, taking over several civilizations, brainwashing their populations, and seizing archives in the Beyond. On the Net, some claim that humans are the means by which the Blight is able to spread. Anti-human fanatics destroy the entire civilization of Sjandra Kei, which is Ravna's home world. The Out of Band II is pursued by three fleets: anti-human fanatics, survivors from Sjandra Kei, and a shadow fleet controlled by the Blight. During the pursuit, Ravna and Pham learn that every member of the Skroderider species can be subverted by the Blight; this drives a wedge between the crew members. Ships from Sjandra Kei sacrifice themselves to delay the Blight and the anti-human ships, allowing the Out of Band II to reach Tine's World before the Blight. When the Out of Band II arrives at Tine's World, the humans ally with Woodcarver to defeat the Flenserists and rescue Jefri. Blueshell sacrifices himself to rescue Jefri. Pham then initiates an anti-Blight Countermeasure, which was aboard the humans' ship. The Countermeasure extends the Slow Zone outward by thousands of light years. This envelops and destroys the Blight, but results in the destruction of thousands of civilizations and trillions of deaths. The humans are stranded on the Tines' World, now in the depths of the Slow Zone. Activating the Countermeasure proves fatal to Pham, but before he dies, the remnant of Old One reveals to him that, although his body is a reconstruction, his memories are indeed real. == Related works == Vinge first used the concepts of "Zones of Thought" in a 1988 novella The Blabber, which occurs after Fire. Vinge's novel A Deepness in the Sky (1999) is a prequel to A Fire Upon the Deep set 20,000 years earlier and featuring Pham Nuwen. Vinge's The Children of the Sky, "a near-term sequel to A Fire Upon the Deep", set ten years later, was released in October 2011. Vinge's former wife, Joan D. Vinge, has also written s
Comparison of raster graphics editors
Raster graphics editors can be compared by many variables, including availability. == List == == General information == Basic general information about the editor: creator, company, license, etc. == Operating system support == The operating systems on which the editors can run natively, that is, without emulation, virtual machines or compatibility layers. In other words, the software must be specifically coded for the operation system; for example, Adobe Photoshop for Windows running on Linux with Wine does not fit. == Features == == Color spaces == == File support ==
Rayid Ghani
Rayid Ghani (born 1977) is a Distinguished Career Professor in the Machine Learning Department (in the School of Computer Science) and the Heinz College of Information Systems and Public Policy at Carnegie Mellon University. Previously, he was the director of the Center for Data Science and Public Policy, research associate professor in the department of computer science, and a senior fellow at the Harris School of Public Policy at the University of Chicago. He was also the co-founder of Edgeflip, an analytics startup that grew out of the Obama 2012 Campaign, focused on social media products for non-profits, advocacy groups, and charities. In September 2019, it was announced that he will be leaving the University of Chicago and joining Carnegie Mellon University's School of Computer Science and Heinz College of Information Systems and Public Policy. Prior to that, Rayid was the Chief Scientist of the Obama 2012 Election Campaign and focused on using data science, machine learning, and technology to improve fundraising, volunteer mobilization, voter registration, persuasion, and turnout. Ghani started and runs the Eric & Wendy Schmidt Data Science for Social Good Summer Fellowship. He's also the co-founder of Coleridge Initiative, a nonprofit organization working with governments to ensure that data and evidence is used more effectively for policymaking. == Education and career == Ghani completed his schooling at the Karachi Grammar School, in Karachi, Pakistan. Ghani completed his graduate studies in the machine learning department at Carnegie Mellon University with Tom M. Mitchell on machine learning and text classification and received his undergraduate degrees in computer science and mathematics from University of the South. Before his role at the University of Chicago, he was the chief scientist of the Obama 2012 Campaign. Before that, he was a senior research scientist and director of analytics research at Accenture Labs, where he led a technology research team focused on applied R&D in analytics, machine learning, and data mining for large-scale and emerging business problems. == Policy efforts == Ghani has been actively working with government agencies and non-profits on designing AI and Machine Learning Systems to help tackle societal problems in public health, criminal justice, social services, education, economic development, and workforce development He has also testified in front of the US Senate in 2023 and the US House of Representatives in 2020, on AI Governance and Regulation. == Research contributions == Ghani's research focuses on developing and applying machine learning, data science, and artificial intelligence methods to large-scale social problems in areas such as education, healthcare, economic development, criminal justice, energy, transportation, and public safety. His work has previously focused on text analytics, fundraising, volunteer, and voter mobilization using analytics, social media, and machine learning., and data mining. Rayid's research contributions have been in the areas of text mining, co-training, active learning, consumer behavior modeling, and fraud detection. His research focus has been on 1) dealing with bias and fairness issues in machine learning and AI, 2) designing Human-AI collaborative systems that support people in making decisions, and 3) evaluating AI systems to focus on the entire workflow and outcomes He has given keynote speeches on Analytics and the Presidential Elections (for example at Predictive Analytics World, Digital Leaders Forum, Carnegie Mellon University, and CeBIT Australia), on Business Applications of Data Mining, and Data Science for Social Good. == Selected publications == Big Data and Social Science: A Practical Guide to Methods and Tools. Editors: Ian Foster, Rayid Ghani, Ron Jarmin, Frauke Kreuter, Julia Lane. CRC Press 2016. Empirical observation of negligible fairness–accuracy trade-offs in machine learning for public policy. Kit Rodolfa, Hemank Lamba, Rayid Ghani. Nature Machine Intelligence 2021. Explainable machine learning for public policy: Use cases, gaps, and research directions. Kasun Amarasinghe, Kit T. Rodolfa, Hemank Lamba, Rayid Ghani. Data and Policy 2023. Data Mining for Business Applications. Editors: Carlos Soares, Rayid Ghani. Book. IOS Press 2010. Mining the Web to Add Semantics to Retail Data Mining. R. Ghani. Invited Paper. Web Mining: From Web to Semantic Web. Springer Lecture Notes in Artificial Intelligence, Vol. 3209. Berendt, B.; Hotho, A.; Mladenic, D.; van Someren, M.; Spiliopoulou, M.; Stumme, G. (Eds.) 2004
Top 10 Conversational AI Platforms Compared (2026)
In search of the best conversational AI platform? An conversational AI platform is software that uses machine learning to help you get more done — it turns a rough idea into a polished result in seconds. When choosing one, weigh output quality, pricing, export formats, and how well it fits the tools you already use. Whether you are a beginner or a pro, the right conversational AI platform slots into your workflow and pays for itself fast. We tested the leading options and ranked them by quality, value, and ease of use.
Karen Spärck Jones
Karen Ida Boalth Spärck Jones (26 August 1935 – 4 April 2007) was a self-taught programmer and a pioneering British computer and information scientist responsible for the concept of inverse document frequency (IDF), a technology that underlies most modern search engines. She was an advocate for women in computer science, her slogan being, "Computing is too important to be left to men." In 2019, The New York Times published her belated obituary in its series Overlooked, calling her "a pioneer of computer science for work combining statistics and linguistics, and an advocate for women in the field." From 2008, to recognise her achievements in the fields of information retrieval (IR) and natural language processing (NLP), the Karen Spärck Jones Award is awarded annually to a recipient for outstanding research in one or both of her fields. == Early life and education == Karen Ida Boalth Spärck Jones was born in Huddersfield, Yorkshire, England. Her parents were Alfred Owen Jones, a chemistry lecturer, and Ida Spärck, a Norwegian who worked for the Norwegian government while in exile in London during World War II. Spärck Jones was educated at a grammar school in Huddersfield and then from 1953 to 1956 at Girton College, Cambridge, studying history, with an additional final year in Moral Sciences (philosophy). While at Cambridge, Spärck Jones joined the organisation known as the Cambridge Language Research Unit (CLRU) and met the head of CLRU Margaret Masterman, who would inspire her to go into computer science. While working at the CLRU, Spärck Jones began pursuing her PhD. At the time of submission, her PhD thesis was cast aside as uninspired and lacking original thought, but was later published in its entirety as a book. She briefly became a school teacher before moving into computer science. Spärck Jones married fellow Cambridge computer scientist Roger Needham in 1958. Spärck Jones's mother, Ida Spärck, had fled Norway on one of the last boats out after the German invasion in April 1940, going on to serve the Norwegian government in exile in London throughout the war. This background of displacement and resilience shaped the household in which Spärck Jones grew up. She later kept her mother's Norwegian surname professionally after marrying, stating that "it maintains a permanent existence of your own." Spärck Jones described her entry into computing as almost accidental. She had been working as a schoolteacher when she began visiting the CLRU out of curiosity about her husband's work. It was Margaret Masterman — whom she later described as "a very strange and interesting woman" — who offered her a research position and drew her fully into the field. == Career == Spärck Jones worked at the Cambridge Language Research Unit from the late 1950s, then at Cambridge University Computer Laboratory from 1974 until her retirement in 2002. From 1999, she held the post of Professor of Computers and Information. She had been given a permanent position only in 1993, and earlier in her career had been employed on a series of short-term contracts. She continued to work in the Computer Laboratory until shortly before her death. Her publications include nine books and numerous papers. A full list of her publications is available from the Cambridge Computer Laboratory. Spärck Jones' main research interests, since the late 1950s, were natural language processing and information retrieval. In 1964, Spärck Jones published "Synonymy and Semantic Classification", which is now seen as a foundational paper in the field of natural language processing. One of her most important contributions was the concept of inverse document frequency (IDF) weighting in information retrieval, which she introduced in a 1972 paper. IDF is used in most search engines today, usually as part of the term frequency–inverse document frequency (TF–IDF) weighting scheme. In the 1980s, Spärck Jones began her work on early speech recognition systems. In 1982 she became involved in the Alvey Programme which was an initiative to motivate more computer science research across the country. == Significance of inverse document frequency == At the time Spärck Jones was working, most computer scientists were focused on making people adapt to machines — learning precise codes and commands to retrieve information. Spärck Jones was working in the opposite direction: teaching computers to understand human language as it is actually used. Her 1972 paper introduced the concept of inverse document frequency (IDF) by observing that not all words carry equal informational value. A word like "the" appears in virtually every document and tells a retrieval system almost nothing about what any specific document is about. A rare word like "photosynthesis," by contrast, is highly specific and informative. IDF assigns each word a statistical weight based on how rarely it occurs across a document collection — the rarer the word, the higher its weight. When combined with term frequency (TF), which measures how often a word appears within a single document, the resulting TF–IDF score gives every word a relevance rating that can be used to rank documents in response to a search query. By 2007, Spärck Jones noted that "pretty much every web engine uses those principles." Her colleague John Tait remarked that "a lot of the stuff she was working on until five or ten years ago seemed like mad nonsense, and now we take it for granted." The 1972 paper remains among the most cited works in information retrieval research, with over 4,500 citations recorded in Google Scholar at the time of her death. The conceptual foundation of TF–IDF — that word meaning is statistical and contextual — has also informed later developments in machine learning and natural language processing, including transformer-based language models such as BERT. == Impact on artificial intelligence == Even though Spärck Jones' views on artificial intelligence (AI) were rather pessimistic in regard to the perceived limitations of AI in information retrieval, her work in natural language processing, information retrieval, and introducing the concept of inverse document frequency (IDF) contributed to the future technological development of AI. Her statistical and ranking methods shifted the direction of the development of AI towards being more expandable and led by data. Her work had a more indirect and conceptual impact on AI, compared to the current and direct impact it has had on search engines. == Gender and advocacy == Spärck Jones spent the majority of her career at Cambridge on short-term contracts without permanent employment, a situation she attributed directly to gender. In her 2001 IEEE oral history interview she stated that Cambridge was "in many ways not user-friendly, in the sense of women-friendly." She was frequently the only woman present in professional meetings throughout her career. She channelled this experience into active advocacy. She was a founding member of the women@cl network at Cambridge's Computer Laboratory, worked on outreach programmes aimed at encouraging girls into computing, and became widely known for her slogan: "Computing is too important to be left to men." She was the first woman ever to receive the BCS Lovelace Medal. === Honours and awards === These include: Gerard Salton Award (1988) Elected a Fellow of Association for the Advancement of Artificial Intelligence (AAAI) in 1993 President of the Association for Computational Linguistics (ACL) in 1994 Honorary degree of Doctor of Science from The City University in 1997. Elected a Fellow of the British Academy (FBA), where she also served as Vice-President in 2000–2002 Fellow of European Association for Artificial Intelligence (ECCAI) Association for Information Science and Technology (ASIS&T) Award of Merit (2002) Association for Computational Linguistics (ACL) Lifetime Achievement Award (2004) ACM - AAAI Allen Newell Award (2006) BCS Lovelace Medal (2007) Association for Computing Machinery (ACM) Women's Group Athena Award (2007) == Death and legacy == Spärck Jones died on 4 April 2007, due to cancer at the age of 71. In 2008, the BCS Information Retrieval Specialist Group (BCS IRSG) in conjunction with the British Computer Society established an annual Karen Spärck Jones Award in her honour, to encourage and promote research that advances understanding of Natural Language Processing or Information Retrieval. The Karen Spärck Jones lecture sponsored by BCS recognises the contribution that women have made to computing. In August 2017, the University of Huddersfield renamed one of its campus buildings in her honour. Formerly known as Canalside West, the Spärck Jones building houses the University's School of Computing and Engineering. When Spärck Jones died in 2007, The Times did not publish an obituary for her, despite having published one for her husband Roger Needham in 2003. In 2019, The New York Times included her in its Overlooked series under the title "Ove
Quantification (machine learning)
In machine learning, quantification (variously called learning to quantify, or supervised prevalence estimation, or class prior estimation) is the task of using supervised learning in order to train models (quantifiers) that estimate the relative frequencies (also known as prevalence values) of the classes of interest in a sample of unlabelled data items. For instance, in a sample of 100,000 unlabelled tweets known to express opinions about a certain political candidate, a quantifier may be used to estimate the percentage of these tweets which belong to class `Positive' (i.e., which manifest a positive stance towards this candidate), and to do the same for classes `Neutral' and `Negative'. Quantification may also be viewed as the task of training predictors that estimate a (discrete) probability distribution, i.e., that generate a predicted distribution that approximates the unknown true distribution of the items across the classes of interest. Quantification is different from classification, since the goal of classification is to predict the class labels of individual data items, while the goal of quantification it to predict the class prevalence values of sets of data items. Quantification is also different from regression, since in regression the training data items have real-valued labels, while in quantification the training data items have class labels. It has been shown in multiple research works that performing quantification by classifying all unlabelled instances and then counting the instances that have been attributed to each class (the 'classify and count' method) usually leads to suboptimal quantification accuracy. This suboptimality may be seen as a direct consequence of 'Vapnik's principle', which states: If you possess a restricted amount of information for solving some problem, try to solve the problem directly and never solve a more general problem as an intermediate step. It is possible that the available information is sufficient for a direct solution but is insufficient for solving a more general intermediate problem. In our case, the problem to be solved directly is quantification, while the more general intermediate problem is classification. As a result of the suboptimality of the 'classify and count' method, quantification has evolved as a task in its own right, different (in goals, methods, techniques, and evaluation measures) from classification. == Quantification tasks == === Quantification tasks according to the set of classes === The main variants of quantification, according to the characteristics of the set of classes used, are: Binary quantification, corresponding to the case in which there are only n = 2 {\displaystyle n=2} classes and each data item belongs to exactly one of them; Single-label multiclass quantification, corresponding to the case in which there are n > 2 {\displaystyle n>2} classes and each data item belongs to exactly one of them; Multi-label multiclass quantification, corresponding to the case in which there are n ≥ 2 {\displaystyle n\geq 2} classes and each data item can belong to zero, one, or several classes at the same time; Ordinal quantification, corresponding to the single-label multiclass case in which a total order is defined on the set of classes. Regression quantification, a task which stands to 'standard' quantification as regression stands to classification. Strictly speaking, this task is not a quantification task as defined above (since the individual items do not have class labels but are labelled by real values), but has enough commonalities with other quantification tasks to be considered one of them. Most known quantification methods address the binary case or the single-label multiclass case, and only few of them address the multi-label, ordinal, and regression cases. Binary-only methods include the Mixture Model (MM) method, the HDy method, SVM(KLD), and SVM(Q). Methods that can deal with both the binary case and the single-label multiclass case include probabilistic classify and count (PCC), adjusted classify and count (ACC), probabilistic adjusted classify and count (PACC), the Saerens-Latinne-Decaestecker EM-based method (SLD), and KDEy. Methods for multi-label quantification include regression-based quantification (RQ) and label powerset-based quantification (LPQ). Methods for the ordinal case include ordinal versions of the above-mentioned ACC, PACC, and SLD methods, and ordinal versions of the above-mentioned HDy method. Methods for the regression case include Regress and splice and Adjusted regress and sum. === Quantification tasks according to the type of data === Several subtasks of quantification may be identified according to the type of data involved. Example such tasks are: Quantification of networked data. This task consists of performing quantification when the datapoints are members of a relation, i.e., are interlinked. As such, this task is a strict relative of collective classification. Quantification over time. This task consists of performing quantification on sets that become available in a temporal sequence, i.e., as a data stream, and finds application in contexts in which class prevalence values must be monitored over time. == Evaluation measures for quantification == Several evaluation measures can be used for evaluating the error of a quantification method. Since quantification consists of generating a predicted probability distribution that estimates a true probability distribution, these evaluation measures are ones that compare two probability distributions. Most evaluation measures for quantification belong to the class of divergences. Evaluation measures for binary quantification, single-label multiclass quantification, and multi-label quantification, are Absolute Error Squared Error Relative Absolute Error Kullback–Leibler divergence Pearson Divergence Evaluation measures for ordinal quantification are Normalized Match Distance (a particular case of the Earth Mover's Distance) Root Normalized Order-Aware Distance == Applications == Quantification is of special interest in fields such as the social sciences, epidemiology, market research, allocating resources, and ecological modelling, since these fields are inherently concerned with aggregate data. However, quantification is also useful as a building block for solving other downstream tasks, such as improving the accuracy of classifiers on out-of-distribution data, measuring classifier bias and ranker bias, and estimating the accuracy of classifiers on out-of-distribution data. == Resources == LQ 2021: the 1st International Workshop on Learning to Quantify LQ 2022: the 2nd International Workshop on Learning to Quantify LQ 2023: the 3rd International Workshop on Learning to Quantify LQ 2024: the 4th International Workshop on Learning to Quantify LQ 2025: the 5th International Workshop on Learning to Quantify LeQua 2022: the 1st Data Challenge on Learning to Quantify LeQua 2024: the 2nd Data Challenge on Learning to Quantify QuaPy: An open-source Python-based software library for quantification QuantificationLib: A Python library for quantification and prevalence estimation
AI Avatar Generators Reviews: What Actually Works in 2026
Shopping for the best AI avatar generator? An AI avatar generator is software that uses machine learning to help you get more done — it keeps getting smarter as the underlying models improve. Pricing, accuracy, and the size of the model behind the tool are the three factors that most affect daily usefulness. Whether you are a beginner or a pro, the right AI avatar generator slots into your workflow and pays for itself fast. Below we compare features, pricing, and real output so you can choose with confidence.