logging in or signing up 1 Chloe Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 348 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (1) Added: November 05, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript ФИЗИКО-ХИМИЧЕСКИЕОСНОВЫНАНОТЕХНОЛОГИИ: ФИЗИКО-ХИМИЧЕСКИЕ ОСНОВЫ НАНОТЕХНОЛОГИИ Профессор Н.Г. РамбидиI. Исходные предпосылки: I. Исходные предпосылкиThe term “Nanotechnology”: The term “Nanotechnology” Coined in 1974 by Nori Taniguchi to mean precision machining with tolerances of a micrometer or less Popularized by Drexler in 1986 By analogy with microtechnology micro = one-millionth (10-6) nano = one-billionth (10-9) Actually, 10-100 nm sequential miniaturization: sequential miniaturization From Powers of Ten, by Philip and Phylis Morrison and the office of Charles and Ray Eames. Definition: Definition The creation of functional materials, devices and systems through control of matter (atomic, molecular and macromolecular levels) at the scale of 1 to 100 nanometers, and exploitation of novel properties and phenomena at the same scale. Nanotechnology lets us fabricate an entire new generation of products that are cleaner, stronger, lighter, and more precise. What is nanotechnology?: What is nanotechnology? Nanotechnology involves the manipulation of objects on the atomic level. Products will be built with every atom in the right place, allowing materials to be lighter, stronger, smarter, cheaper, cleaner, and more precise. In order for this science to be realized, positional control must be achieved, and self-replication is necessary to reduce costs.Исходные посылки: Исходные посылки Два основных вопроса: Какой все-таки смысл вкладывается в понятие «нанотехнология»? Почему именно сейчас возник нанотехнологический бум?Экономические и социальные корни нанотехнологического бума: Экономические и социальные корни нанотехнологического бума Демографические взрывы Сокращение природных ресурсов Глобальная информационная система Глобальная транспортная система Изменение социальных мотивацийСинтез природного каучука как пример нанотехнологического подхода: Синтез природного каучука как пример нанотехнологического подходаSlide10: Полимеризация этилена, стирола, хлорвинилаSlide11: Структурные варианты полимерных системSlide12: Синтетические каучукиSlide14: Синтез природного каучукаSlide15: Синтез природного каучукаSlide16: Синтез природного каучукаКорни нанотехнологического бума: Корни нанотехнологического бумаИсходная и основная причина возникновения нанотехнологии: Исходная и основная причина возникновения нанотехнологии Развитие информационных технологий, вызванное все увеличивающейся значимостью сложных динамических систем, необходимостью понимания их механизмов и управления имиСложные динамические системы: Сложные динамические системыСложные динамические системы: Сложные динамические системы Многоуровневая структура Распределенная динамика Нелинейные динамические механизмы Развитая система обратных связейBees: Bees Colony cooperation Regulate hive temperature Efficiency via Specialization: division of labour in the colony Communication : Food sources are exploited according to quality and distance from the hiveTermites: Termites Cone-shaped outer walls and ventilation ducts Brood chambers in central hive Spiral cooling vents Support pillarsAnts: Ants Organizing highways to and from their foraging sites by leaving pheromone trails Form chains from their own bodies to create a bridge to pull and hold leafs together with silk Division of labour between major and minor ants Slide25: Question: How can ag systems be quantified & used to understand rural poverty and resource degradation? Hypothesis: Spatial heterogeneity and dynamic properties of these systems are key to understanding their behavior (and linkages to poverty & degradation) e.g., in understanding non-adoption of conservation techs A key question is how much detail is needed to answer important policy questions!!! The soil microbial system: The soil microbial system More diversity in the palm of your hand than in the mammalian kingdom Most important and abused ecosystem in the world Essential features Species concept not useful Feedback and feedforward coupling to dynamic environment is central Functionality Can’t measure much (anything)Have you ever done something in a crowd you’d never have done alone? : If you had to move furniture, would you work better in a group, or alone? What if you were writing a term paper? Have you ever had a bad supervisor? What differentiated that person from a good supervisor? Have you ever done something in a crowd you’d never have done alone? The Nature of Groups: The Nature of Groups Group - Two or more people who influence each other. Collections of individuals become increasingly “group like” when they: Are interdependent Share a common identity Have a group structureCrowds and Deindividuation: Crowds and Deindividuation Deindividuation - The process of losing one’s sense of personal identity, which: makes it easier to behave in ways inconsistent with one’s normal values. Example: Anonymous children in Halloween costumes stole more from a candy jar (Beaman et al., 1979)Slide30: In an initial vote, the opinions looked like the above. Red circles depict neighbors who are Anti-party Blue circles depict neighbors who are Pro-party What will happen if everyone checks with his or her immediate neighbors, and goes with the local majority? Copyright © 2002 by Allyn and BaconSlide31: This individual will change because the majority of her neighbors are “Anti” Copyright © 2002 by Allyn and BaconSlide32: But this neighbor will change because the majority of his neighbors are “Pro” With all this changing back and forth, what will happen over the course of a few weeks? Copyright © 2002 by Allyn and BaconSlide33: Because local majorities draw in people in their vicinity, the neighborhood will eventually stabilize into this pattern. Copyright © 2002 by Allyn and BaconПроблемы «искусственного интеллекта» как подход к пониманию сложных динамических систем: Проблемы «искусственного интеллекта» как подход к пониманию сложных динамических системAI Defenitions: AI DefenitionsApplied Areas of AI: Applied Areas of AI Game playing Speech and language processing Expert reasoning Planning and scheduling Vision RoboticsSlide37: IMPORTANT TO SCIENCE 1. What is the nature of matter? 2. What is the nature of life? 3. What is the nature of mind? Slide38: IMPORTANT TO ECONOMIC PROSPERITY Toffler's Three Waves 1. Invention of agriculture 2. Invention of steam engine and discovery of electricity 3. Invention of electronics and digital computerSlide39: IMPORTANT FOR ECONOMIC PROSPERITY Manufacturing Business management and financial services Marketing and customer services Transportation safety and efficiency Communications Construction Waste management and cleanup Health care Physical security Agriculture and food processing Mining and drilling Space and undersea explorationSlide40: IMPORTANT FOR MILITARY STRENGTH 1. Intelligent systems will enable a new generation of unmanned vehicles and weapon systems that will: 2. Intelligent systems technologies will enable: -- outperform manned systems -- with fewer casualties -- and lower cost for training and readiness -- faster information gathering and processing -- more rapid replanning for real-time events -- and more effective command and controlSlide41: IMPORTANT FOR MILITARY STRENGTH 1. Intelligent systems will enable a new generation of unmanned vehicles and weapon systems that will: 2. Intelligent systems technologies will enable: -- outperform manned systems -- with fewer casualties -- and lower cost for training and readiness -- faster information gathering and processing -- more rapid replanning for real-time events -- and more effective command and controlSlide42: IMPORTANT FOR HUMAN WELL BEING Clean up the environment Improve health care Improve transportation safety and efficiency Improve personal services and security Improve productivity End poverty and create golden ageThe background of intellectual problems: The background of intellectual problems Recognition of images, scenes and situations Investigation of the system evolution having complicated behavioral dynamics Choice of optimal structure or behavior of multifactor systems having complex branching search tree Control problemsBiological roots of intellectual problems: Biological roots of intellectual problemsBiological roots of intellectual problems: Biological roots of intellectual problemsсложность: сложностьAndrey Nikolaevich Kolmogorov: Andrey Nikolaevich Kolmogorov Born: April 25, 1903 Tambov, Russia Died: Oct. 20, 1987“Complexity”: Organisms :1000 to 100,000 genes Boeing 777 : >100,000 subsystems and ... …many subsystems are highly complex. Engine: > 10,000 subsystems Laptop: >1,000,000,000 transistors Refinery : > 10,000 integral feedback loops High rise heating-ventilation-AC: > 1000 Internet, power grid, etc.: ~ “Complexity”Definitions and Properties: Definitions and Properties Complexity Non-linear interaction among multiple components Complicated versus complex systems Irreducible Local and distributed Non-deterministic / unpredictable Emergence / self-organization Deterministic Reductionist principle Dynamic / stochastic HolisticNonlinearity in Spread of Innovation: Nonlinearity in Spread of Innovation Cumulative number of farmers Year Source: Based on Ryan and Gross (1943) Number of Adopters of Hybrid Seed Corn in Two Iowa Communitiesалгоритмическая сложность: алгоритмическая сложность min l(p) : (px)=y K(yx) = { : pS (px)yComputational Complexity: Computational Complexity P: Problems with time complexity of O(nk) where, k is a constant. P-type problems are classically tractable or easy. Problems with exponential complexity such as O(NN), O(2N), O(N!) are classically intractable or “hard”. NP: A solution, if exists, can be verified in polynomial time. NP-complete: NP and “hard” or intractable classically.Slide53: Логистическое уравнениеПроблема «Коммивояжер»: Проблема «Коммивояжер» { Vin,1,2,3..N, Vout } fixed Vin ,Vout P{1,2,3..N} N! pathsПроблема «Коммивояжер»: Проблема «Коммивояжер»Slide61: Combinatorial Explosion A 10 city TSP has 181,000 possible solutions A 20 city TSP has 10,000,000,000,000,000 possible solutions A 50 City TSP has 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 possible solutions There are 1,000,000,000,000,000,000,000 litres of water on the planet Mchalewicz, Z, Evolutionary Algorithms for Constrained Optimization Problems, CEC 2000 (Tutorial)Проблема «Коммивояжер»исходная система (100 точек): Проблема «Коммивояжер» исходная система (100 точек)Проблема «Коммивояжер»после 500 итераций: Проблема «Коммивояжер» после 500 итерацийПроблема «Коммивояжер»после 4000 итераций: Проблема «Коммивояжер» после 4000 итерацийРеакционно-диффузионная среда: Реакционно-диффузионная средаСредаБелоусова-Жаботинского: Среда Белоусова-ЖаботинскогоНейросетевой подходкак инструмент эффективного решения задач высокой вычислительной сложности: Нейросетевой подход как инструмент эффективного решения задач высокой вычислительной сложностиПринципы парадигмы фон Неймана: Принципы парадигмы фон Неймана Вводимая извне программа Последовательное выполнение операций Программа записывается теми же кодами, что и данные, что позволяет изменять программу в ходе вычислений (разветвления, циклы) Простейшие двоичные элементарные операции, позволяющие создать универсальный вычислительThe brain: The brain The cortex 1.3-1.4kg (2% of the body weight) … [13,14] 2,500 cm2 (rat: 6 cm2, elephant: 6,300 cm2) [14] 1,300-1,500 cm3 2 hemispheres connected by corpus callossum (250 mill. nerve fibers) Inputs: spinal cord optic nerve (1.2 mill.) cranial nerves (12) auditory system, … Neurons : Neurons 100 billion neurons (children) loss: ~1/sec 31 million/year Octopus: 300 million Diameter: 4 – 100 microns Weight: 10-6 grams Length: <1 mm – 4 feet (in the leg) [15] Length of Giraffe primary afferent axon: 15 feet The brain as a computational system: The brain as a computational system The brain is biological de-central (plasticity) non-digital highly parallel What does this mean? The Biological Neuron : The Biological Neuron 10 billion neurons in human brain Summation of input stimuli Spatial (signals) Temporal (pulses) Threshold over composed inputs Constant firing strengthBiological Neural Networks: Biological Neural Networks 10,000 synapses per neuron Computational power = connectivity Plasticity new connections (?) strength of connections modified Artificial Neuron: Artificial Neuron Abstract away from almost everything except connectivity…Binary Neurons: Binary Neurons “Hard” threshold = threshold ex: Perceptrons, Hopfield NNs, Boltzmann Machines Main drawbacks: can only map binary functions, biologically implausible. off on Stimulus ResponseAnalog Neurons: Analog Neurons “Soft” threshold ex: MLPs, Recurrent NNs, RBF NNs... Main drawbacks: difficult to process time patterns, biologically implausible. off on Stimulus ResponseArtificial Neural Networks: Artificial Neural Networks Output layer Input layer Hidden layers fully connected sparsely connectedNeural network mathematics: Neural network mathematics Inputs OutputКогда аппаратные возможности компьютера сравняются с возможностями человеческого мозга?: Когда аппаратные возможности компьютера сравняются с возможностями человеческого мозга?Slide85: The most powerful experimental supercomputers in 1998 composed of thousands or tents of thousands of the fastest microprocessors and costing tens of millions of dollars can do a few million MIPS. They are within striking distance of being powerful enough to match human brainpower, but are unlikely to be applied to that end. Why tie up a rare twenty-million-dollar asset to develop one erzatz-human, when millions of inexpensive original-model humans are available. Such machines are needed for high-value scientific calculations, physical simulations, having no cheaper substitute. AI research must wait for the power to become more affordable. H. Moravec “When will computer hardware match the human brain?” Некоторые перспективы: Некоторые перспективыSlide87: Ферменты – принцип «ключ-замок»Slide88: Механизм ферментативной реакцииThree historical trendsin manufacturing: Three historical trends in manufacturing More flexible More precise Less expensive You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
1 Chloe Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINTLite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 348 Category: Entertainment License: All Rights Reserved Like it (0) Dislike it (1) Added: November 05, 2007 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript ФИЗИКО-ХИМИЧЕСКИЕОСНОВЫНАНОТЕХНОЛОГИИ: ФИЗИКО-ХИМИЧЕСКИЕ ОСНОВЫ НАНОТЕХНОЛОГИИ Профессор Н.Г. РамбидиI. Исходные предпосылки: I. Исходные предпосылкиThe term “Nanotechnology”: The term “Nanotechnology” Coined in 1974 by Nori Taniguchi to mean precision machining with tolerances of a micrometer or less Popularized by Drexler in 1986 By analogy with microtechnology micro = one-millionth (10-6) nano = one-billionth (10-9) Actually, 10-100 nm sequential miniaturization: sequential miniaturization From Powers of Ten, by Philip and Phylis Morrison and the office of Charles and Ray Eames. Definition: Definition The creation of functional materials, devices and systems through control of matter (atomic, molecular and macromolecular levels) at the scale of 1 to 100 nanometers, and exploitation of novel properties and phenomena at the same scale. Nanotechnology lets us fabricate an entire new generation of products that are cleaner, stronger, lighter, and more precise. What is nanotechnology?: What is nanotechnology? Nanotechnology involves the manipulation of objects on the atomic level. Products will be built with every atom in the right place, allowing materials to be lighter, stronger, smarter, cheaper, cleaner, and more precise. In order for this science to be realized, positional control must be achieved, and self-replication is necessary to reduce costs.Исходные посылки: Исходные посылки Два основных вопроса: Какой все-таки смысл вкладывается в понятие «нанотехнология»? Почему именно сейчас возник нанотехнологический бум?Экономические и социальные корни нанотехнологического бума: Экономические и социальные корни нанотехнологического бума Демографические взрывы Сокращение природных ресурсов Глобальная информационная система Глобальная транспортная система Изменение социальных мотивацийСинтез природного каучука как пример нанотехнологического подхода: Синтез природного каучука как пример нанотехнологического подходаSlide10: Полимеризация этилена, стирола, хлорвинилаSlide11: Структурные варианты полимерных системSlide12: Синтетические каучукиSlide14: Синтез природного каучукаSlide15: Синтез природного каучукаSlide16: Синтез природного каучукаКорни нанотехнологического бума: Корни нанотехнологического бумаИсходная и основная причина возникновения нанотехнологии: Исходная и основная причина возникновения нанотехнологии Развитие информационных технологий, вызванное все увеличивающейся значимостью сложных динамических систем, необходимостью понимания их механизмов и управления имиСложные динамические системы: Сложные динамические системыСложные динамические системы: Сложные динамические системы Многоуровневая структура Распределенная динамика Нелинейные динамические механизмы Развитая система обратных связейBees: Bees Colony cooperation Regulate hive temperature Efficiency via Specialization: division of labour in the colony Communication : Food sources are exploited according to quality and distance from the hiveTermites: Termites Cone-shaped outer walls and ventilation ducts Brood chambers in central hive Spiral cooling vents Support pillarsAnts: Ants Organizing highways to and from their foraging sites by leaving pheromone trails Form chains from their own bodies to create a bridge to pull and hold leafs together with silk Division of labour between major and minor ants Slide25: Question: How can ag systems be quantified & used to understand rural poverty and resource degradation? Hypothesis: Spatial heterogeneity and dynamic properties of these systems are key to understanding their behavior (and linkages to poverty & degradation) e.g., in understanding non-adoption of conservation techs A key question is how much detail is needed to answer important policy questions!!! The soil microbial system: The soil microbial system More diversity in the palm of your hand than in the mammalian kingdom Most important and abused ecosystem in the world Essential features Species concept not useful Feedback and feedforward coupling to dynamic environment is central Functionality Can’t measure much (anything)Have you ever done something in a crowd you’d never have done alone? : If you had to move furniture, would you work better in a group, or alone? What if you were writing a term paper? Have you ever had a bad supervisor? What differentiated that person from a good supervisor? Have you ever done something in a crowd you’d never have done alone? The Nature of Groups: The Nature of Groups Group - Two or more people who influence each other. Collections of individuals become increasingly “group like” when they: Are interdependent Share a common identity Have a group structureCrowds and Deindividuation: Crowds and Deindividuation Deindividuation - The process of losing one’s sense of personal identity, which: makes it easier to behave in ways inconsistent with one’s normal values. Example: Anonymous children in Halloween costumes stole more from a candy jar (Beaman et al., 1979)Slide30: In an initial vote, the opinions looked like the above. Red circles depict neighbors who are Anti-party Blue circles depict neighbors who are Pro-party What will happen if everyone checks with his or her immediate neighbors, and goes with the local majority? Copyright © 2002 by Allyn and BaconSlide31: This individual will change because the majority of her neighbors are “Anti” Copyright © 2002 by Allyn and BaconSlide32: But this neighbor will change because the majority of his neighbors are “Pro” With all this changing back and forth, what will happen over the course of a few weeks? Copyright © 2002 by Allyn and BaconSlide33: Because local majorities draw in people in their vicinity, the neighborhood will eventually stabilize into this pattern. Copyright © 2002 by Allyn and BaconПроблемы «искусственного интеллекта» как подход к пониманию сложных динамических систем: Проблемы «искусственного интеллекта» как подход к пониманию сложных динамических системAI Defenitions: AI DefenitionsApplied Areas of AI: Applied Areas of AI Game playing Speech and language processing Expert reasoning Planning and scheduling Vision RoboticsSlide37: IMPORTANT TO SCIENCE 1. What is the nature of matter? 2. What is the nature of life? 3. What is the nature of mind? Slide38: IMPORTANT TO ECONOMIC PROSPERITY Toffler's Three Waves 1. Invention of agriculture 2. Invention of steam engine and discovery of electricity 3. Invention of electronics and digital computerSlide39: IMPORTANT FOR ECONOMIC PROSPERITY Manufacturing Business management and financial services Marketing and customer services Transportation safety and efficiency Communications Construction Waste management and cleanup Health care Physical security Agriculture and food processing Mining and drilling Space and undersea explorationSlide40: IMPORTANT FOR MILITARY STRENGTH 1. Intelligent systems will enable a new generation of unmanned vehicles and weapon systems that will: 2. Intelligent systems technologies will enable: -- outperform manned systems -- with fewer casualties -- and lower cost for training and readiness -- faster information gathering and processing -- more rapid replanning for real-time events -- and more effective command and controlSlide41: IMPORTANT FOR MILITARY STRENGTH 1. Intelligent systems will enable a new generation of unmanned vehicles and weapon systems that will: 2. Intelligent systems technologies will enable: -- outperform manned systems -- with fewer casualties -- and lower cost for training and readiness -- faster information gathering and processing -- more rapid replanning for real-time events -- and more effective command and controlSlide42: IMPORTANT FOR HUMAN WELL BEING Clean up the environment Improve health care Improve transportation safety and efficiency Improve personal services and security Improve productivity End poverty and create golden ageThe background of intellectual problems: The background of intellectual problems Recognition of images, scenes and situations Investigation of the system evolution having complicated behavioral dynamics Choice of optimal structure or behavior of multifactor systems having complex branching search tree Control problemsBiological roots of intellectual problems: Biological roots of intellectual problemsBiological roots of intellectual problems: Biological roots of intellectual problemsсложность: сложностьAndrey Nikolaevich Kolmogorov: Andrey Nikolaevich Kolmogorov Born: April 25, 1903 Tambov, Russia Died: Oct. 20, 1987“Complexity”: Organisms :1000 to 100,000 genes Boeing 777 : >100,000 subsystems and ... …many subsystems are highly complex. Engine: > 10,000 subsystems Laptop: >1,000,000,000 transistors Refinery : > 10,000 integral feedback loops High rise heating-ventilation-AC: > 1000 Internet, power grid, etc.: ~ “Complexity”Definitions and Properties: Definitions and Properties Complexity Non-linear interaction among multiple components Complicated versus complex systems Irreducible Local and distributed Non-deterministic / unpredictable Emergence / self-organization Deterministic Reductionist principle Dynamic / stochastic HolisticNonlinearity in Spread of Innovation: Nonlinearity in Spread of Innovation Cumulative number of farmers Year Source: Based on Ryan and Gross (1943) Number of Adopters of Hybrid Seed Corn in Two Iowa Communitiesалгоритмическая сложность: алгоритмическая сложность min l(p) : (px)=y K(yx) = { : pS (px)yComputational Complexity: Computational Complexity P: Problems with time complexity of O(nk) where, k is a constant. P-type problems are classically tractable or easy. Problems with exponential complexity such as O(NN), O(2N), O(N!) are classically intractable or “hard”. NP: A solution, if exists, can be verified in polynomial time. NP-complete: NP and “hard” or intractable classically.Slide53: Логистическое уравнениеПроблема «Коммивояжер»: Проблема «Коммивояжер» { Vin,1,2,3..N, Vout } fixed Vin ,Vout P{1,2,3..N} N! pathsПроблема «Коммивояжер»: Проблема «Коммивояжер»Slide61: Combinatorial Explosion A 10 city TSP has 181,000 possible solutions A 20 city TSP has 10,000,000,000,000,000 possible solutions A 50 City TSP has 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 possible solutions There are 1,000,000,000,000,000,000,000 litres of water on the planet Mchalewicz, Z, Evolutionary Algorithms for Constrained Optimization Problems, CEC 2000 (Tutorial)Проблема «Коммивояжер»исходная система (100 точек): Проблема «Коммивояжер» исходная система (100 точек)Проблема «Коммивояжер»после 500 итераций: Проблема «Коммивояжер» после 500 итерацийПроблема «Коммивояжер»после 4000 итераций: Проблема «Коммивояжер» после 4000 итерацийРеакционно-диффузионная среда: Реакционно-диффузионная средаСредаБелоусова-Жаботинского: Среда Белоусова-ЖаботинскогоНейросетевой подходкак инструмент эффективного решения задач высокой вычислительной сложности: Нейросетевой подход как инструмент эффективного решения задач высокой вычислительной сложностиПринципы парадигмы фон Неймана: Принципы парадигмы фон Неймана Вводимая извне программа Последовательное выполнение операций Программа записывается теми же кодами, что и данные, что позволяет изменять программу в ходе вычислений (разветвления, циклы) Простейшие двоичные элементарные операции, позволяющие создать универсальный вычислительThe brain: The brain The cortex 1.3-1.4kg (2% of the body weight) … [13,14] 2,500 cm2 (rat: 6 cm2, elephant: 6,300 cm2) [14] 1,300-1,500 cm3 2 hemispheres connected by corpus callossum (250 mill. nerve fibers) Inputs: spinal cord optic nerve (1.2 mill.) cranial nerves (12) auditory system, … Neurons : Neurons 100 billion neurons (children) loss: ~1/sec 31 million/year Octopus: 300 million Diameter: 4 – 100 microns Weight: 10-6 grams Length: <1 mm – 4 feet (in the leg) [15] Length of Giraffe primary afferent axon: 15 feet The brain as a computational system: The brain as a computational system The brain is biological de-central (plasticity) non-digital highly parallel What does this mean? The Biological Neuron : The Biological Neuron 10 billion neurons in human brain Summation of input stimuli Spatial (signals) Temporal (pulses) Threshold over composed inputs Constant firing strengthBiological Neural Networks: Biological Neural Networks 10,000 synapses per neuron Computational power = connectivity Plasticity new connections (?) strength of connections modified Artificial Neuron: Artificial Neuron Abstract away from almost everything except connectivity…Binary Neurons: Binary Neurons “Hard” threshold = threshold ex: Perceptrons, Hopfield NNs, Boltzmann Machines Main drawbacks: can only map binary functions, biologically implausible. off on Stimulus ResponseAnalog Neurons: Analog Neurons “Soft” threshold ex: MLPs, Recurrent NNs, RBF NNs... Main drawbacks: difficult to process time patterns, biologically implausible. off on Stimulus ResponseArtificial Neural Networks: Artificial Neural Networks Output layer Input layer Hidden layers fully connected sparsely connectedNeural network mathematics: Neural network mathematics Inputs OutputКогда аппаратные возможности компьютера сравняются с возможностями человеческого мозга?: Когда аппаратные возможности компьютера сравняются с возможностями человеческого мозга?Slide85: The most powerful experimental supercomputers in 1998 composed of thousands or tents of thousands of the fastest microprocessors and costing tens of millions of dollars can do a few million MIPS. They are within striking distance of being powerful enough to match human brainpower, but are unlikely to be applied to that end. Why tie up a rare twenty-million-dollar asset to develop one erzatz-human, when millions of inexpensive original-model humans are available. Such machines are needed for high-value scientific calculations, physical simulations, having no cheaper substitute. AI research must wait for the power to become more affordable. H. Moravec “When will computer hardware match the human brain?” Некоторые перспективы: Некоторые перспективыSlide87: Ферменты – принцип «ключ-замок»Slide88: Механизм ферментативной реакцииThree historical trendsin manufacturing: Three historical trends in manufacturing More flexible More precise Less expensive