Artificial intelligence
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TOPIO, a humanoid robot, played ping pong at Tokyo International Robot Exhibition (IREX) 2009.[1][2]
Artificial intelligence (AI) is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents"[3] where an intelligent agent is a system that perceives its environment and takes actions that maximize its chances of success.[4] John McCarthy, who coined the term in 1956,[5] defines it as "the science and engineering of making intelligent machines."[6]
The field was founded on the claim that a central property of humans, intelligence—the sapience of Homo sapiens—can be so precisely described that it can be simulated by a machine.[7] This raises philosophical issues about the nature of the mind and the ethics of creating artificial beings, issues which have been addressed by myth, fiction and philosophy since antiquity.[8] Artificial intelligence has been the subject of optimism,[9] but has also suffered setbacks[10] and, today, has become an essential part of the technology industry, providing the heavy lifting for many of the most difficult problems in computer science.[11]
AI research is highly technical and specialized, deeply divided into subfields that often fail to communicate with each other.[12] Subfields have grown up around particular institutions, the work of individual researchers, the solution of specific problems, longstanding differences of opinion about how AI should be done and the application of widely differing tools. The central problems of AI include such traits as reasoning, knowledge, planning, learning, communication, perception and the ability to move and manipulate objects.[13] General intelligence (or "strong AI") is still among the field's long term goals.[14]
Thinking machines and artificial beings appear in Greek myths, such as Talos of Crete, the bronze robot of Hephaestus and Pygmalion's Galatea.[15] Human likenesses believed to have intelligence were built in every major civilization: animated statues were seen in Egypt and Greece[16] and humanoid automatons were built by Yan Shi,[17] Hero of Alexandria,[18] Al-Jazari[19] and Wolfgang von Kempelen.[20] It was also widely believed that artificial beings had been created by Jābir ibn Hayyān,[21] Judah Loew[22] and Paracelsus.[23] By the 19th and 20th centuries, artificial beings had become a common feature in fiction, as in Mary Shelley's Frankenstein or Karel Čapek's R.U.R. (Rossum's Universal Robots).[24] Pamela McCorduck argues that all of these are examples of an ancient urge, as she describes it, "to forge the gods".[8] Stories of these creatures and their fates discuss many of the same hopes, fears and ethical concerns that are presented by artificial intelligence.
Mechanical or "formal" reasoning has been developed by philosophers and mathematicians since antiquity. The study of logic led directly to the invention of the programmable digital electronic computer, based on the work of mathematician Alan Turing and others. Turing's theory of computation suggested that a machine, by shuffling symbols as simple as "0" and "1", could simulate any conceivable act of mathematical deduction.[25] This, along with recent discoveries in neurology, information theory and cybernetics, inspired a small group of researchers to begin to seriously consider the possibility of building an electronic brain.[26]
The field of AI research was founded at a conference on the campus of Dartmouth College in the summer of 1956.[27] The attendees, including John McCarthy, Marvin Minsky, Allen Newell and Herbert Simon, became the leaders of AI research for many decades.[28] They and their students wrote programs that were, to most people, simply astonishing:[29] computers were solving word problems in algebra, proving logical theorems and speaking English.[30] By the middle of the 1960s, research in the U.S. was heavily funded by the Department of Defense[31] and laboratories had been established around the world.[32] AI's founders were profoundly optimistic about the future of the new field: Herbert Simon predicted that "machines will be capable, within twenty years, of doing any work a man can do"[33] and Marvin Minsky agreed, writing that "within a generation ... the problem of creating 'artificial intelligence' will substantially be solved".[34]
They had failed to recognize the difficulty of some of the problems they faced.[35] In 1974, in response to the criticism of England's Sir James Lighthill and ongoing pressure from Congress to fund more productive projects, the U.S. and British governments cut off all undirected, exploratory research in AI. The next few years, when funding for projects was hard to find, would later be called an "AI winter".[36]
In the early 1980s, AI research was revived by the commercial success of expert systems,[37] a form of AI program that simulated the knowledge and analytical skills of one or more human experts. By 1985 the market for AI had reached over a billion dollars. At the same time, Japan's fifth generation computer project inspired the U.S and British governments to restore funding for academic research in the field.[38] However, beginning with the collapse of the Lisp Machine market in 1987, AI once again fell into disrepute, and a second, longer lasting AI winter began.[39]
In the 1990s and early 21st century, AI achieved its greatest successes, albeit somewhat behind the scenes. Artificial intelligence is used for logistics, data mining, medical diagnosis and many other areas throughout the technology industry.[11] The success was due to several factors: the increasing computational power of computers (see Moore's law), a greater emphasis on solving specific subproblems, the creation of new ties between AI and other fields working on similar problems, and a new commitment by researchers to solid mathematical methods and rigorous scientific standards.[40]
The general problem of simulating (or creating) intelligence has been broken down into a number of specific sub-problems. These consist of particular traits or capabilities that researchers would like an intelligent system to display. The traits described below have received the most attention.[13]
Early AI researchers developed algorithms that imitated the step-by-step reasoning that humans were often assumed to use when they solve puzzles, play board games or make logical deductions.[41] By the late 1980s and '90s, AI research had also developed highly successful methods for dealing with uncertain or incomplete information, employing concepts from probability and economics.[42]
For difficult problems, most of these algorithms can require enormous computational resources — most experience a "combinatorial explosion": the amount of memory or computer time required becomes astronomical when the problem goes beyond a certain size. The search for more efficient problem solving algorithms is a high priority for AI research.[43]
Human beings solve most of their problems using fast, intuitive judgments rather than the conscious, step-by-step deduction that early AI research was able to model.[44] AI has made some progress at imitating this kind of "sub-symbolic" problem solving: embodied agent approaches emphasize the importance of sensorimotor skills to higher reasoning; neural net research attempts to simulate the structures inside human and animal brains that give rise to this skill.
Knowledge representation[45] and knowledge engineering[46] are central to AI research. Many of the problems machines are expected to solve will require extensive knowledge about the world. Among the things that AI needs to represent are: objects, properties, categories and relations between objects;[47] situations, events, states and time;[48] causes and effects;[49] knowledge about knowledge (what we know about what other people know);[50] and many other, less well researched domains. A complete representation of "what exists" is an ontology[51] (borrowing a word from traditional philosophy), of which the most general are called upper ontologies.
Among the most difficult problems in knowledge representation are:
Many of the things people know take the form of "working assumptions." For example, if a bird comes up in conversation, people typically picture an animal that is fist sized, sings, and flies. None of these things are true about all birds. John McCarthy identified this problem in 1969[52] as the qualification problem: for any commonsense rule that AI researchers care to represent, there tend to be a huge number of exceptions. Almost nothing is simply true or false in the way that abstract logic requires. AI research has explored a number of solutions to this problem.[53]
The breadth of commonsense knowledge
The number of atomic facts that the average person knows is astronomical. Research projects that attempt to build a complete knowledge base of commonsense knowledge (e.g., Cyc) require enormous amounts of laborious ontological engineering — they must be built, by hand, one complicated concept at a time.[54] A major goal is to have the computer understand enough concepts to be able to learn by reading from sources like the internet, and thus be able to add to its own ontology.[citation needed]
The subsymbolic form of some commonsense knowledge
Much of what people know is not represented as "facts" or "statements" that they could express verbally. For example, a chess master will avoid a particular chess position because it "feels too exposed"[55] or an art critic can take one look at a statue and instantly realize that it is a fake.[56] These are intuitions or tendencies that are represented in the brain non-consciously and sub-symbolically.[57] Knowledge like this informs, supports and provides a context for symbolic, conscious knowledge. As with the related problem of sub-symbolic reasoning, it is hoped that situated AI or computational intelligence will provide ways to represent this kind of knowledge.[57]
Main article: Automated planning and scheduling
Intelligent agents must be able to set goals and achieve them.[58] They need a way to visualize the future (they must have a representation of the state of the world and be able to make predictions about how their actions will change it) and be able to make choices that maximize the utility (or "value") of the available choices.[59]
In classical planning problems, the agent can assume that it is the only thing acting on the world and it can be certain what the consequences of its actions may be.[60] However, if this is not true, it must periodically check if the world matches its predictions and it must change its plan as this becomes necessary, requiring the agent to reason under uncertainty.[61]
Multi-agent planning uses the cooperation and competition of many agents to achieve a given goal. Emergent behavior such as this is used by evolutionary algorithms and swarm intelligence.[62]
Main article: Machine learning
Machine learning[63] has been central to AI research from the beginning.[64] Unsupervised learning is the ability to find patterns in a stream of input. Supervised learning includes both classification and numerical regression. Classification is used to determine what category something belongs in, after seeing a number of examples of things from several categories. Regression takes a set of numerical input/output examples and attempts to discover a continuous function that would generate the outputs from the inputs. In reinforcement learning[65] the agent is rewarded for good responses and punished for bad ones. These can be analyzed in terms of decision theory, using concepts like utility. The mathematical analysis of machine learning algorithms and their performance is a branch of theoretical computer science known as computational learning theory.
ASIMO uses sensors and intelligent algorithms to avoid obstacles and navigate stairs.
Main article: Natural language processing
Natural language processing[66] gives machines the ability to read and understand the languages that humans speak. Many researchers hope that a sufficiently powerful natural language processing system would be able to acquire knowledge on its own, by reading the existing text available over the internet. Some straightforward applications of natural language processing include information retrieval (or text mining) and machine translation.[67]
Main article: Robotics
The field of robotics[68] is closely related to AI. Intelligence is required for robots to be able to handle such tasks as object manipulation[69] and navigation, with sub-problems of localization (knowing where you are), mapping (learning what is around you) and motion planning (figuring out how to get there).[70]
Machine perception[71] is the ability to use input from sensors (such as cameras, microphones, sonar and others more exotic) to deduce aspects of the world. Computer vision[72] is the ability to analyze visual input. A few selected subproblems are speech recognition,[73] facial recognition and object recognition.[74]
Main article: Affective computing
Kismet, a robot with rudimentary social skills
Emotion and social skills[75] play two roles for an intelligent agent. First, it must be able to predict the actions of others, by understanding their motives and emotional states. (This involves elements of game theory, decision theory, as well as the ability to model human emotions and the perceptual skills to detect emotions.) Also, for good human-computer interaction, an intelligent machine also needs to display emotions. At the very least it must appear polite and sensitive to the humans it interacts with. At best, it should have normal emotions itself.
Main article: Computational creativity
A sub-field of AI addresses creativity both theoretically (from a philosophical and psychological perspective) and practically (via specific implementations of systems that generate outputs that can be considered creative, or systems that identify and assess creativity). A related area of computational research is Artificial Intuition and Artificial Imagination.
Most researchers hope that their work will eventually be incorporated into a machine with general intelligence (known as strong AI), combining all the skills above and exceeding human abilities at most or all of them.[14] A few believe that anthropomorphic features like artificial consciousness or an artificial brain may be required for such a project.[76]
Many of the problems above are considered AI-complete: to solve one problem, you must solve them all. For example, even a straightforward, specific task like machine translation requires that the machine follow the author's argument (reason), know what is being talked about (knowledge), and faithfully reproduce the author's intention (social intelligence). Machine translation, therefore, is believed to be AI-complete: it may require strong AI to be done as well as humans can do it.[77]
There is no established unifying theory or paradigm that guides AI research. Researchers disagree about many issues.[78] A few of the most long standing questions that have remained unanswered are these: should artificial intelligence simulate natural intelligence, by studying psychology or neurology? Or is human biology as irrelevant to AI research as bird biology is to aeronautical engineering?[79] Can intelligent behavior be described using simple, elegant principles (such as logic or optimization)? Or does it necessarily require solving a large number of completely unrelated problems?[80] Can intelligence be reproduced using high-level symbols, similar to words and ideas? Or does it require "sub-symbolic" processing?[81]
In the 1940s and 1950s, a number of researchers explored the connection between neurology, information theory, and cybernetics. Some of them built machines that used electronic networks to exhibit rudimentary intelligence, such as W. Grey Walter's turtles and the Johns Hopkins Beast. Many of these researchers gathered for meetings of the Teleological Society at Princeton University and the Ratio Club in England.[26] By 1960, this approach was largely abandoned, although elements of it would be revived in the 1980s.
Main article: GOFAI
When access to digital computers became possible in the middle 1950s, AI research began to explore the possibility that human intelligence could be reduced to symbol manipulation. The research was centered in three institutions: CMU, Stanford and MIT, and each one developed its own style of research. John Haugeland named these approaches to AI "good old fashioned AI" or "GOFAI".[82]
Cognitive simulation
Economist Herbert Simon and Allen Newell studied human problem solving skills and attempted to formalize them, and their work laid the foundations of the field of artificial intelligence, as well as cognitive science, operations research and management science. Their research team used the results of psychological experiments to develop programs that simulated the techniques that people used to solve problems. This tradition, centered at Carnegie Mellon University would eventually culminate in the development of the Soar architecture in the middle 80s.[83][84]
Logic based
Unlike Newell and Simon, John McCarthy felt that machines did not need to simulate human thought, but should instead try to find the essence of abstract reasoning and problem solving, regardless of whether people used the same algorithms.[79] His laboratory at Stanford (SAIL) focused on using formal logic to solve a wide variety of problems, including knowledge representation, planning and learning.[85] Logic was also focus of the work at the University of Edinburgh and elsewhere in Europe which led to the development of the programming language Prolog and the science of logic programming.[86]
"Anti-logic" or "scruffy"
Researchers at MIT (such as Marvin Minsky and Seymour Papert)[87] found that solving difficult problems in vision and natural language processing required ad-hoc solutions – they argued that there was no simple and general principle (like logic) that would capture all the aspects of intelligent behavior. Roger Schank described their "anti-logic" approaches as "scruffy" (as opposed to the "neat" paradigms at CMU and Stanford).[80] Commonsense knowledge bases (such as Doug Lenat's Cyc) are an example of "scruffy" AI, since they must be built by hand, one complicated concept at a time.[88]
Knowledge based
When computers with large memories became available around 1970, researchers from all three traditions began to build knowledge into AI applications.[89] This "knowledge revolution" led to the development and deployment of expert systems (introduced by Edward Feigenbaum), the first truly successful form of AI software.[37] The knowledge revolution was also driven by the realization that enormous amounts of knowledge would be required by many simple AI applications.
During the 1960s, symbolic approaches had achieved great success at simulating high-level thinking in small demonstration programs. Approaches based on cybernetics or neural networks were abandoned or pushed into the background.[90] By the 1980s, however, progress in symbolic AI seemed to stall and many believed that symbolic systems would never be able to imitate all the processes of human cognition, especially perception, robotics, learning and pattern recognition. A number of researchers began to look into "sub-symbolic" approaches to specific AI problems.[81]
Researchers from the related field of robotics, such as Rodney Brooks, rejected symbolic AI and focused on the basic engineering problems that would allow robots to move and survive.[91] Their work revived the non-symbolic viewpoint of the early cybernetics researchers of the 50s and reintroduced the use of control theory in AI. This coincided with the development of the embodied mind thesis in the related field of cognitive science: the idea that aspects of the body (such as movement, perception and visualization) are required for higher intelligence.
Computational Intelligence
Interest in neural networks and "connectionism" was revived by David Rumelhart and others in the middle 1980s.[92] These and other sub-symbolic approaches, such as fuzzy systems and evolutionary computation, are now studied collectively by the emerging discipline of computational intelligence.[93]
In the 1990s, AI researchers developed sophisticated mathematical tools to solve specific subproblems. These tools are truly scientific, in the sense that their results are both measurable and verifiable, and they have been responsible for many of AI's recent successes. The shared mathematical language has also permitted a high level of collaboration with more established fields (like mathematics, economics or operations research). Stuart Russell and Peter Norvig describe this movement as nothing less than a "revolution" and "the victory of the neats."[40]
Intelligent agent paradigm
An intelligent agent is a system that perceives its environment and takes actions which maximizes its chances of success. The simplest intelligent agents are programs that solve specific problems. The most complicated intelligent agents are rational, thinking humans.[94] The paradigm gives researchers license to study isolated problems and find solutions that are both verifiable and useful, without agreeing on one single approach. An agent that solves a specific problem can use any approach that works — some agents are symbolic and logical, some are sub-symbolic neural networks and others may use new approaches. The paradigm also gives researchers a common language to communicate with other fields—such as decision theory and economics—that also use concepts of abstract agents. The intelligent agent paradigm became widely accepted during the 1990s.[95]
Researchers have designed systems to build intelligent systems out of interacting intelligent agents in a multi-agent system.[96] A system with both symbolic and sub-symbolic components is a hybrid intelligent system, and the study of such systems is artificial intelligence systems integration. A hierarchical control system provides a bridge between sub-symbolic AI at its lowest, reactive levels and traditional symbolic AI at its highest levels, where relaxed time constraints permit planning and world modelling.[97] Rodney Brooks' subsumption architecture was an early proposal for such a hierarchical system.
In the course of 50 years of research, AI has developed a large number of tools to solve the most difficult problems in computer science. A few of the most general of these methods are discussed below.
Many problems in AI can be solved in theory by intelligently searching through many possible solutions:[98] Reasoning can be reduced to performing a search. For example, logical proof can be viewed as searching for a path that leads from premises to conclusions, where each step is the application of an inference rule.[99] Planning algorithms search through trees of goals and subgoals, attempting to find a path to a target goal, a process called means-ends analysis.[100] Robotics algorithms for moving limbs and grasping objects use local searches in configuration space.[69] Many learning algorithms use search algorithms based on optimization.
Simple exhaustive searches[101] are rarely sufficient for most real world problems: the search space (the number of places to search) quickly grows to astronomical numbers. The result is a search that is too slow or never completes. The solution, for many problems, is to use "heuristics" or "rules of thumb" that eliminate choices that are unlikely to lead to the goal (called "pruning the search tree"). Heuristics supply the program with a "best guess" for what path the solution lies on.[102]
A very different kind of search came to prominence in the 1990s, based on the mathematical theory of optimization. For many problems, it is possible to begin the search with some form of a guess and then refine the guess incrementally until no more refinements can be made. These algorithms can be visualized as blind hill climbing: we begin the search at a random point on the landscape, and then, by jumps or steps, we keep moving our guess uphill, until we reach the top. Other optimization algorithms are simulated annealing, beam search and random optimization.[103]
Evolutionary computation uses a form of optimization search. For example, they may begin with a population of organisms (the guesses) and then allow them to mutate and recombine, selecting only the fittest to survive each generation (refining the guesses). Forms of evolutionary computation include swarm intelligence algorithms (such as ant colony or particle swarm optimization)[104] and evolutionary algorithms (such as genetic algorithms[105] and genetic programming[106][107]).
Logic[108] is used for knowledge representation and problem solving, but it can be applied to other problems as well. For example, the satplan algorithm uses logic for planning[109] and inductive logic programming is a method for learning.[110]
Several different forms of logic are used in AI research. Propositional or sentential logic[111] is the logic of statements which can be true or false. First-order logic[112] also allows the use of quantifiers and predicates, and can express facts about objects, their properties, and their relations with each other. Fuzzy logic,[113] is a version of first-order logic which allows the truth of a statement to be represented as a value between 0 and 1, rather than simply True (1) or False (0). Fuzzy systems can be used for uncertain reasoning and have been widely used in modern industrial and consumer product control systems. Subjective logic models uncertainty in a different and more explicit manner than fuzzy-logic: a given binomial opinion satisfies belief + disbelief + uncertainty = 1 within a Beta distribution. By this method, ignorance can be distinguished from probabilistic statements that an agent makes with high confidence. Default logics, non-monotonic logics and circumscription[53] are forms of logic designed to help with default reasoning and the qualification problem. Several extensions of logic have been designed to handle specific domains of knowledge, such as: description logics;[47] situation calculus, event calculus and fluent calculus (for representing events and time);[48] causal calculus;[49] belief calculus; and modal logics.[50]
Main articles: Bayesian network, Hidden Markov model, Kalman filter, Decision theory, and Utility theory
Many problems in AI (in reasoning, planning, learning, perception and robotics) require the agent to operate with incomplete or uncertain information. AI researchers have devised a number of powerful tools to solve these problems using methods from probability theory and economics.[114]
Bayesian networks[115] are a very general tool that can be used for a large number of problems: reasoning (using the Bayesian inference algorithm),[116] learning (using the expectation-maximization algorithm),[117] planning (using decision networks)[118] and perception (using dynamic Bayesian networks).[119] Probabilistic algorithms can also be used for filtering, prediction, smoothing and finding explanations for streams of data, helping perception systems to analyze processes that occur over time[120] (e.g., hidden Markov models[121] or Kalman filters[122]).
A key concept from the science of economics is "utility": a measure of how valuable something is to an intelligent agent. Precise mathematical tools have been developed that analyze how an agent can make choices and plan, using decision theory, decision analysis,[123] information value theory.[59] These tools include models such as Markov decision processes,[124] dynamic decision networks,[124] game theory and mechanism design.[125]
The simplest AI applications can be divided into two types: classifiers ("if shiny then diamond") and controllers ("if shiny then pick up"). Controllers do however also classify conditions before inferring actions, and therefore classification forms a central part of many AI systems. Classifiers are functions that use pattern matching to determine a closest match. They can be tuned according to examples, making them very attractive for use in AI. These examples are known as observations or patterns. In supervised learning, each pattern belongs to a certain predefined class. A class can be seen as a decision that has to be made. All the observations combined with their class labels are known as a data set. When a new observation is received, that observation is classified based on previous experience.[126]
A classifier can be trained in various ways; there are many statistical and machine learning approaches. The most widely used classifiers are the neural network,[127] kernel methods such as the support vector machine,[128] k-nearest neighbor algorithm,[129] Gaussian mixture model,[130] naive Bayes classifier,[131] and decision tree.[132] The performance of these classifiers have been compared over a wide range of tasks. Classifier performance depends greatly on the characteristics of the data to be classified. There is no single classifier that works best on all given problems; this is also referred to as the "no free lunch" theorem. Determining a suitable classifier for a given problem is still more an art than science.[133]
A neural network is an interconnected group of nodes, akin to the vast network of neurons in the human brain.
The study of artificial neural networks[127] began in the decade before the field AI research was founded, in the work of Walter Pitts and Warren McCullough. Other important early researchers were Frank Rosenblatt, who invented the perceptron and Paul Werbos who developed the backpropagation algorithm.[134]
The main categories of networks are acyclic or feedforward neural networks (where the signal passes in only one direction) and recurrent neural networks (which allow feedback). Among the most popular feedforward networks are perceptrons, multi-layer perceptrons and radial basis networks.[135] Among recurrent networks, the most famous is the Hopfield net, a form of attractor network, which was first described by John Hopfield in 1982.[136] Neural networks can be applied to the problem of intelligent control (for robotics) or learning, using such techniques as Hebbian learning and competitive learning.[137]
Jeff Hawkins argues that research in neural networks has stalled because it has failed to model the essential properties of the neocortex, and has suggested a model (Hierarchical Temporal Memory) that is loosely based on neurological research.[138]
Main article: Intelligent control
Control theory, the grandchild of cybernetics, has many important applications, especially in robotics.[139]
AI researchers have developed several specialized languages for AI research, including Lisp[140] and Prolog.[141]
Main article: Progress in artificial intelligence
In 1950, Alan Turing proposed a general procedure to test the intelligence of an agent now known as the Turing test. This procedure allows almost all the major problems of artificial intelligence to be tested. However, it is a very difficult challenge and at present all agents fail.
Artificial intelligence can also be evaluated on specific problems such as small problems in chemistry, hand-writing recognition and game-playing. Such tests have been termed subject matter expert Turing tests. Smaller problems provide more achievable goals and there are an ever-increasing number of positive results.
The broad classes of outcome for an AI test are:
- Optimal: it is not possible to perform better
- Strong super-human: performs better than all humans
- Super-human: performs better than most humans
- Sub-human: performs worse than most humans
For example, performance at draughts is optimal,[142] performance at chess is super-human and nearing strong super-human,[143] and performance at many everyday tasks performed by humans is sub-human.
A quite different approach measures machine intelligence through tests which are developed from mathematical definitions of intelligence. Examples of these kinds of tests start in the late nineties devising intelligence tests using notions from Kolmogorov Complexity and data compression.[144][145][146] Two major advantages of mathematical definitions are their applicability to nonhuman intelligences and their absence of a requirement for human testers.
Main article: Applications of artificial intelligence
Artificial intelligence techniques are pervasive and are too numerous to list. Frequently, when a technique reaches mainstream use, it is no longer considered artificial intelligence; this phenomenon is described as the AI effect.[147]
Main article: Competitions and prizes in artificial intelligence
There are a number of competitions and prizes to promote research in artificial intelligence. The main areas promoted are: general machine intelligence, conversational behavior, data-mining, driverless cars, robot soccer and games.
A platform (or "computing platform")is defined as "some sort of hardware architecture or software framework (including application frameworks), that allows software to run." As Rodney Brooks [148] pointed out many years ago, it is not just the artificial intelligence software that defines the AI features of the platform, but rather the actual platform itself that affects the AI that results, i.e., we need to be working out AI problems on real world platforms rather than in isolation.
A wide variety of platforms has allowed different aspects of AI to develop, ranging from expert systems, albeit PC-based but still an entire real-world system to various robot platforms such as the widely available Roomba with open interface.[149]
Main article: Philosophy of artificial intelligence
Artificial intelligence, by claiming to be able to recreate the capabilities of the human mind, is both a challenge and an inspiration for philosophy. Are there limits to how intelligent machines can be? Is there an essential difference between human intelligence and artificial intelligence? Can a machine have a mind and consciousness? A few of the most influential answers to these questions are given below.[150]
If a machine acts as intelligently as a human being, then it is as intelligent as a human being. Alan Turing theorized that, ultimately, we can only judge the intelligence of a machine based on its behavior. This theory forms the basis of the Turing test.[151]
"Every aspect of learning or any other feature of intelligence can be so precisely described that a machine can be made to simulate it." This assertion was printed in the proposal for the Dartmouth Conference of 1956, and represents the position of most working AI researchers.[152]
"A physical symbol system has the necessary and sufficient means of general intelligent action." Newell and Simon argue that intelligences consists of formal operations on symbols.[153] Hubert Dreyfus argued that, on the contrary, human expertise depends on unconscious instinct rather than conscious symbol manipulation and on having a "feel" for the situation rather than explicit symbolic knowledge. (See Dreyfus' critique of AI.)[154][155]
A formal system (such as a computer program) can not prove all true statements. Roger Penrose is among those who claim that Gödel's theorem limits what machines can do. (See The Emperor's New Mind.)[156][157]
"The appropriately programmed computer with the right inputs and outputs would thereby have a mind in exactly the same sense human beings have minds."[158] John Searle counters this assertion with his Chinese room argument, which asks us to look inside the computer and try to find where the "mind" might be.[159]
The brain can be simulated. Hans Moravec, Ray Kurzweil and others have argued that it is technologically feasible to copy the brain directly into hardware and software, and that such a simulation will be essentially identical to the original.[160]
Main articles: Artificial intelligence in fiction, Ethics of artificial intelligence, Transhumanism, and Technological singularity
Artifcial Intelligence is a common topic in both science fiction and projections about the future of technology and society. The existence of an artificial intelligence that rivals human intelligence raises difficult ethical issues, and the potential power of the technology inspires both hopes and fears.
In fiction, Artificial Intelligence has appeared fulfilling many roles, including a servant (R2D2 in Star Wars), a law enforcer (K.I.T.T. "Knight Rider"), a comrade (Lt. Commander Data in Star Trek: The Next Generation), a conqueror/overlord (The Matrix), a dictator (With Folded Hands), an assassin (Terminator), a sentient race (Battlestar Galactica/Transformers), an extension to human abilities (Ghost in the Shell) and the savior of the human race (R. Daneel Olivaw in the Asimov's Robot Series).
Mary Shelley's Frankenstein[161] considers a key issue in the ethics of artificial intelligence: if a machine can be created that has intelligence, could it also feel? If it can feel, does it have the same rights as a human? The idea also appears in modern science fiction, including the films I Robot, Blade Runner and A.I.: Artificial Intelligence, in which humanoid machines have the ability to feel human emotions. This issue, now known as "robot rights", is currently being considered by, for example, California's Institute for the Future,[162] although many critics believe that the discussion is premature.[163]
Andrew Kennedy, in his musing on the evolution of the human personality,[164] considered that artificial intelligences or 'new minds' are likely to have severe personality disorders, and identifies four particular types that are likely to arise: the autistic, the collector, the ecstatic, and the victim. He suggests that they will need humans because of our superior understanding of personality and the role of the unconscious.
Martin Ford[165] and others[166] argue that specialized artificial intelligence applications, robotics and other forms of automation will ultimately result in significant unemployment as machines begin to match and exceed the capability of workers to perform most routine and repetitive jobs. Ford predicts that many knowledge-based occupations—and in particular entry level jobs—will be increasingly susceptible to automation via expert systems and other AI-enhanced applications. AI-based applications may also be used to amplify the capabilities of low-wage offshore workers, making it more feasible to outsource knowledge work. Evidence to support this contention may be found in the fact that real wages for new college graduates have been flat or even declining since 2000.[167]
Joseph Weizenbaum[168] wrote that AI applications can not, by definition, successfully simulate genuine human empathy and that the use of AI technology in fields such as customer service or psychotherapy[169] was deeply misguided. Weizenbaum was also bothered that AI researchers (and some philosophers) were willing to view the human mind as nothing more than a computer program (a position now known as computationalism). To Weizenbaum these points suggest that AI research devalues human life.
Many futurists believe that artificial intelligence will ultimately transcend the limits of progress. Ray Kurzweil has used Moore's law (which describes the relentless exponential improvement in digital technology) to calculate that desktop computers will have the same processing power as human brains by the year 2029. He also predicts that by 2045 artificial intelligence will reach a point where it is able to improve itself at a rate that far exceeds anything conceivable in the past, a scenario that science fiction writer Vernor Vinge named the "technological singularity".[170]
Robot designer Hans Moravec, cyberneticist Kevin Warwick and inventor Ray Kurzweil have predicted that humans and machines will merge in the future into cyborgs that are more capable and powerful than either.[170] This idea, called transhumanism, which has roots in Aldous Huxley and Robert Ettinger, has been illustrated in fiction as well, for example in the manga Ghost in the Shell and the science-fiction series Dune.
Edward Fredkin argues that "artificial intelligence is the next stage in evolution,"[171] an idea first proposed by Samuel Butler's "Darwin among the Machines" (1863), and expanded upon by George Dyson in his book of the same name in 1998.
Pamela McCorduck writes that all these scenarios are expressions of the ancient human desire to, as she calls it, "forge the gods".[
Intelligent agent
From Wikipedia, the free encyclopedia
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In artificial intelligence, an intelligent agent (IA) is an autonomous entity which observes and acts upon an environment (i.e. it is an agent) and directs its activity towards achieving goals (i.e. it is rational).[1] Intelligent agents may also learn or use knowledge to achieve their goals. They may be very simple or very complex: a reflex machine such as a thermostat is an intelligent agent,[2] as is a human being, as is a community of human beings working together towards a goal.
Simple reflex agent
Intelligent agents are often described schematically as an abstract functional system similar to a computer program. For this reason, intelligent agents are sometimes called abstract intelligent agents (AIA)[citation needed] to distinguish them from their real world implementations as computer systems, biological systems, or organizations. Some definitions of intelligent agents emphasize their autonomy, and so prefer the term autonomous intelligent agents. Still others (notably Russell & Norvig (2003)) considered goal-directed behavior as the essence of intelligence and so prefer a term borrowed from economics, "rational agent".
Intelligent agents in artificial intelligence are closely related to agents in economics, and versions of the intelligent agent paradigm are studied in cognitive science, ethics, the philosophy of practical reason, as well as in many interdisciplinary socio-cognitive modeling and computer social simulations.
Intelligent agents are also closely related to software agents (an autonomous software program that carries out tasks on behalf of users). In computer science, the term intelligent agent may be used to refer to a software agent that has some intelligence, regardless if it is not a rational agent by Russell and Norvig's definition. For example, autonomous programs used for operator assistance or data mining (sometimes referred to as bots) are also called "intelligent agents".
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Intelligent agents have been defined many different ways.[3] According to Nikola Kasabov[4] IA systems should exhibit the following characteristics:
- accommodate new problem solving rules incrementally
- adapt online and in real time
- be able to analyze itself in terms of behavior, error and success.
- learn and improve through interaction with the environment (embodiment)
- learn quickly from large amounts of data
- have memory-based exemplar storage and retrieval capacities
- have parameters to represent short and long term memory, age, forgetting, etc.
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A simple agent program can be defined mathematically as an agent function[5] which maps every possible percepts sequence to a possible action the agent can perform or to a coefficient, feedback element, function or constant that affects eventual actions:
Learning agent
Russell & Norvig (2003) group agents into five classes based on their degree of perceived intelligence and capability:[6]
- simple reflex agents
- model-based reflex agents
- goal-based agents
- utility-based agents
- learning agents
Simple reflex agents
Simple reflex agents act only on the basis of the current percept. The agent function is based on the condition-action rule: if condition then action.
This agent function only succeeds when the environment is fully observable. Some reflex agents can also contain information on their current state which allows them to disregard conditions whose actuators are already triggered.
Model-based reflex agents
A model-based agent can handle a partially observable environment. Its current state is stored inside the agent maintaining some kind of structure which describes the part of the world which cannot be seen. This behavior requires information on how the world behaves and works. This additional information completes the “World View” model.
A model-based reflex agent keeps track of the current state of the world using an internal model. It then chooses an action in the same way as the reflex agent.
Goal-based agents
Goal-based agents are model-based agents which store information regarding situations that are desirable. This allows the agent a way to choose among multiple possibilities, selecting the one which reaches a goal state.
Utility-based agents
Goal-based agents only distinguish between goal states and non-goal states. It is possible to define a measure of how desirable a particular state is. This measure can be obtained through the use of a utility function which maps a state to a measure of the utility of the state.
Learning agents
Learning has an advantage that it allows the agents to initially operate in unknown environments and to become more competent than its initial knowledge alone might allow.
According to other sources[who?], some of the sub-agents (not already mentioned in this treatment) that may be a part of an Intelligent Agent or a complete Intelligent Agent in themselves are:
- Decision Agents (that are geared to decision making);
- Input Agents (that process and make sense of sensor inputs - e.g. neural network based agents);
- Processing Agents (that solve a problem like speech recognition);
- Spatial Agents (that relate to the physical real-world);
- World Agents (that incorporate a combination of all the other classes of agents to allow autonomous behaviors).
- Believable agents - An agent exhibiting a personality via the use of an artificial character (the agent is embedded) for the interaction.
- Physical Agents - A physical agent is an entity which percepts through sensors and acts through actuators.
- Temporal Agents - A temporal agent may use time based stored information to offer instructions or data acts to a computer program or human being and takes program inputs percepts to adjust its next behaviors.
Main article: Multi-agent system
To actively perform their functions, Intelligent Agents today are normally gathered in a hierarchical structure containing many “sub-agents”. Intelligent sub-agents process and perform lower level functions. Taken together, the intelligent agent and sub-agents create a complete system that can accomplish difficult tasks or goals with behaviors and responses that display a form of intelligence.[citation needed]
Intelligent Systems Co., Ltd. (株式会社インテリジェントシステムズ Kabushiki-Gaisha Interijento Shisutemuzu?) is a Japanese first-party video game developer and internal team of Nintendo Co., Ltd. It has its headquarters in the Nintendo Kyoto Research Center in Higashiyama-ku, Kyoto, Kyoto Prefecture.[1]Intelligent Systems entered the video game industry as a one-man team, named Toru Narihiro, who was hired by Nintendo to port over Famicom Disk software into the standard ROM-cartridge format that was being used by the NES outside Japan. The team soon became an auxiliary program unit for Nintendo (like HAL Laboratory originally) that provided system tools and hired people to program, fix, or port Nintendo-developed software. Thus much of the team's original discography contains minuscule contributions to several big Nintendo R&D1 and Nintendo EAD titles.
Chief programmer Toru Narihiro programmed his first actual game software with Famicom Wars and Fire Emblem towards the end of the Famicom's life cycle, although the game design, graphic design, and music was provided by the Nintendo R&D1 team. But because of Narihiro's success, Intelligent Systems began to hire graphic designers, programmers, and even musicians to extend the company from an auxiliary–tool developer to an actual game development group.
Intelligent Systems currently focuses on DS and Wii development, and has developed games for all of Nintendo's previous handhelds and consoles.
Contents |
[edit] List of games
[edit] Hardware
| Game | Date | Notes | ||
[edit] Consoles[edit] Nintendo Entertainment System (Family Computer) | ||||
| Fire Emblem: Ankoku Ryū to Hikari no Ken (with Nintendo R&D1) | 4/20/90 | Japan only. The first in the Fire Emblem series. Co-developed with Nintendo R&D1. | ||
| 3/14/92 | Japan only. Co-developed with Nintendo R&D1. | |||
| Devil World (assisted game program) | 10/5/84 | Contributed programming to Nintendo EAD. | ||
| Wild Gunman (assisted game program) | 10/18/85 | Contributed programming to Nintendo R&D1. | ||
| 7/12/88 | First in the Famicom Wars series. Contributed programming to Nintendo R&D1. | |||
[edit] Super Nintendo Entertainment System (Super Famicom) | ||||
| Japan only. The sequel to the Japan only turn-based strategy game. | ||||
| The third entry in the Metroid series. (Design and Music by Nintendo R&D1, Program by Intelligent Systems) | ||||
| Japan only. A puzzle game starring a young girl named Lip. It was released in the United States under the name Tetris Attack, and re-released in the Japan only Nintendo Puzzle Collection. | ||||
| The American adaptation of Panel de Pon, using characters from Super Mario World 2: Yoshi's Island. Starred Yoshi and Little Yoshi in various quests against Bowser and his minions in order to save their friends, doing puzzle fights between them and the enemies (The Game Boy version was later released in Japan as "Yoshi no Panepon"). | ||||
| Known as Space Bazooka in Japan. It uses the Super Scope accessory. Co-developed with Nintendo R&D1. | ||||
| Japan only. Contains a remake of and sequel to the original Fire Emblem game. | ||||
| Japan only. Spans two generations of characters. | ||||
| Japan only. The last Fire Emblem game released for the Super Famicom/SNES. It takes place between chapters 5 and 6 of Fire Emblem: Seisen no Keifu. | ||||
| The sequel to Battle Clash, which was only released in North America and Europe. | ||||
[edit] Virtual Boy | ||||
[edit] Nintendo 64 | ||||
| The quasi-sequel to Super Mario RPG: Legend of the Seven Stars, featuring a new Paper style of visuals, and new style of gameplay. | ||||
| Fire Emblem 64 | Cancelled - The Nintendo 64 installment in the Fire Emblem series. No screenshots were released however early screenshots of Fire Emblem: Fuuin no Tsurugi display a radical change in graphics and style from the game's final build, as well as include characters that were nowhere to be seen in the game. This, along with the game's original title, "Maiden in the Darkness," and the fact that at one point in Fuuin no Tsurugi one character is surreptitiously given that title, has caused speculation that perhaps much of the game's story and/or mechanics was transferred onto the Game Boy Advance.[citation needed] | |||
[edit] GameCube | ||||
| The sequel to Paper Mario. | ||||
| The ninth game in the Fire Emblem series. | ||||
| Contributed partial programming and partial design with Nintendo R&D1. | ||||
[edit] Wii | ||||
| The tenth game in the Fire Emblem series. | ||||
| The fifth game in the WarioWare series. | ||||
| The third game in the Paper Mario series. | ||||
| WiiWare Game | ||||
| WiiWare Game | ||||
[edit] Game handhelds[edit] Game Boy | ||||
| 04/21/89 | Launch title | |||
| Launch title | ||||
| Japan only | ||||
| Golf | Launch title | |||
| A Nintendo R&D1 game designed by Nintendo's Yoshio Sakamoto. Intelligent Systems supplemented the programming. | ||||
| Yakuman | Japan only, launch title | |||
[edit] Game Boy Color | ||||
[edit] Game Boy Advance | ||||
| Japan only, the sixth game of the Fire Emblem series. | ||||
| The first of the Fire Emblem series to be released outside of Japan. It is the seventh title of the series. | ||||
| The eighth title of the Fire Emblem series. | ||||
| Worked on the Puzzle League part only | ||||
[edit] Nintendo DS | ||||
| Known as Famicom Wars DS in Japan | ||||
| Known as Advance Wars: Dark Conflict in Europe and Australia | ||||
| Designed by Nintendo's Software Planning & Development team. Programmed by Intelligent Systems. | ||||
| Released as the DSiWare title | ||||
| Remake of Fire Emblem: Ankoku Ryū to Hikari no Ken and the eleventh game of the series. | ||||
[edit] Nintendo 3DS | ||||
| Fourth installment in the Paper Mario series. | ||||
[edit] References
- ^ "Location." (Direct map link) (Direct directions diagram link) Intelligent Systems. Retrieved on August 29, 2010.
- Intelligent Systems website, game listing (Japanese)
- Intelligent Systems website, game listing (English)
[edit] External links
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- Official website
- Official website (Japanese)
- Intelligent Systems profile on MobyGames
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Retrieved from "http://en.wikipedia.org/wiki/Intelligent_Systems"
Categories: Intelligent Systems | First-party video game developers | Japanese video game companies | Video game developers | Companies based in Kyoto Prefecture
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