Matched:%20common%20in%20homoepitaxy,%20sometimes%20in%20heteroepitaxy - PowerPoint PPT Presentation

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Matched:%20common%20in%20homoepitaxy,%20sometimes%20in%20heteroepitaxy

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Title: 1 Author: Rambidi Last modified by: Rambidi Created Date: 11/15/2004 8:59:10 AM Document presentation format: Company – PowerPoint PPT presentation

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Title: Matched:%20common%20in%20homoepitaxy,%20sometimes%20in%20heteroepitaxy


1
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  • ????????? ?.?. ???????

2
13. ???????????????
3
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4
??????????????? ??? ??????????? ?????????????
5
????????????????
  • Matched common in homoepitaxy, sometimes in
    heteroepitaxy

6
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7
????????????????
micelle
cross section
reverse micelle
cross section
8
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9
Systems Self-Organization in Natural
  • What are the mechanisms for integrating subunits
    activity into a coherently structured entity?
  • From simple neurons to the thinking brain
  • From individuals to the society
  • From molecule to pattern

10
Self-Organization in Natural Systems
  • What are the mechanisms for integrating subunits
    activity into a coherently structured entity?
  • From simple neurons to the thinking brain
  • From individuals to the society
  • From molecule to pattern

C3H4O4 NaBr NaBrO3 HSO3 C12H8N2SO2Fe
Malonic acid Sodium bromide Sodium
bromate Sulfuric acid 1,10 Phenanthroline ferrous
sulfate
11
Definitions
  • What is Chaos ? Poincarré Lorenz Prigogine
  • disorder, confusion, is opposed to order and
    method
  • Chaos define a particular state of a system
    that is characterized by the following behaviors
  • Do not repeat
  • Sensible to initial conditions sharp differences
    can produce wide divergent results
  • Moreover, ordered and characterized by an
    unpredictable determinism
  • When moving away from equillibrium state gt high
    organization
  • Non equillibrium phasis bifurcations
  • Amplification gt Symetry break

12
Definitions
  • What is Self-organization in natural systems?
  • Self-organization is a process in which pattern
    at the global level of a system emerges solely
    from numerous interactions among the lower level
    components of the system. Deneubourg 1977
  • Moreover, the rules specifying interactions
    among the systems components are executed using
    only local information, without reference to the
    global pattern
  • In other words, the pattern is an emergent
    property of the system, rather than a property
    imposed on the system by an external influence

13
Definitions
  • What is an emergent property ?
  • Many Agents
  • Simple rules
  • Many interactions
  • Decentralization
  • Emergent properties
  • Unreductibility
  • Macro-level (odre magnitude difference)
  • Feed-back effect on the micro-level

Conditions
Observations
14
Self-Organization in Natural Systems
CONDENSED MATTER
COMPLEX SYSTEMS
Solid State Physics Soft Matter Granular Materials Cell Biology Economics
Fundamental particles electrons, holes, photons polymers, lipids, colloids... beads, grains proteins, ATP,DNA/RNA. companies,  banks...
DiversityHeterogeneity Low Modest heteropolymers Modest High High
Interactions given by Hamiltonian given by effective Hamiltonian  (Free Energy) dissipative  mechanics chemical kinetics is  adequate many unknown parameters non-deterministic, often irrational
Macroscopic Observable resistance, magnetization order parameters, viscosity,  elasticity... stress, velocity, density... phenotype,  functional changes.. GNP, inflation, Dow Johns index...
  • A physical point of view

15
Non-living pattern formation
  • Based on physical and chemical properties
  • Belousov-Zhabotinsky reaction
  • Bénard convection cells
  • Sand dune ripples
  • Glass cracks
  • Mud cracks

16
Non-living pattern formation
  • Based on physical and chemical properties
  • Belousov-Zhabotinsky reaction
  • Bénard convection cells
  • Sand dune ripples
  • Glass cracks
  • Mud cracks

17
Non-living pattern formation
  • Based on physical and chemical properties
  • Belousov-Zhabotinsky reaction
  • Bénard convection cells
  • Sand dune ripples
  • Glass cracks
  • Mud cracks

18
Non-living pattern formation
  • Based on physical and chemical properties
  • Belousov-Zhabotinsky reaction
  • Bénard convection cells
  • Sand dune ripples
  • Glass cracks
  • Mud cracks

19
Non-living pattern formation
  • Based on physical and chemical properties
  • Belousov-Zhabotinsky reaction
  • Bénard convection cells
  • Sand dune ripples
  • Glass cracks
  • Mud cracks

20
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21
Pattern formation in biological systems
  • Patterns characterizing individuals
  • Giraffe coat
  • Zebra
  • Leopard
  • Vermiculated rabbitfish
  • Cone shells
  • Finger prints
  • Morel
  • Metamerization
  • Occular dominance stripes

22
Pattern formation in biological systems
  • Patterns characterizing individuals
  • Giraffe coat
  • Zebra
  • Leopard
  • Vermiculated rabbitfish
  • Cone shells
  • Finger prints
  • Morel
  • Metamerization
  • Occular dominance stripes

23
Pattern formation in biological systems
  • Patterns characterizing individuals
  • Giraffe coat
  • Zebra
  • Leopard
  • Vermiculated rabbitfish
  • Cone shells
  • Finger prints
  • Morel
  • Metamerization
  • Occular dominance stripes

24
Pattern formation in biological systems
  • Patterns characterizing individuals
  • Giraffe coat
  • Zebra
  • Leopard
  • Vermiculated rabbitfish
  • Cone shells
  • Finger prints
  • Morel
  • Metamerization
  • Occular dominance stripes

25
Pattern formation in biological systems
  • Patterns characterizing individuals
  • Giraffe coat
  • Zebra
  • Leopard
  • Vermiculated rabbitfish
  • Cone shells
  • Finger prints
  • Morel
  • Metamerisation
  • Occular dominance stripes

26
Pattern formation in biological systems
  • Most of those patterns are in fact fixed states
    of reactions that have occurred long time ago
  • Patterns characterizing individuals
  • Giraffe coat
  • Zebra
  • Leopard
  • Vermiculated rabbitfish
  • Cone shells
  • Finger prints
  • Morel
  • Metamerisation
  • Occular dominance stripes

or process is still running.
Mechanisms ?
27
Pattern formation in biological systems
  • Patterns occurring during collective movement
  • Microorganisms
  • Insects and Crustaceans
  • Social insects
  • Fishes
  • Birds
  • Mammalians

28
Pattern formation in biological systems
  • Patterns occurring during collective movement
  • Microorganisms
  • Insects and Crustaceans
  • Social insects
  • Fishes
  • Birds
  • Mammalians

29
Pattern formation in biological systems
  • Patterns occurring during collective movement
  • Microorganisms
  • Insects and Crustaceans
  • Social insects
  • Fishes
  • Birds
  • Mammalians
  • Those patterns results from a permanent
    reorganization

mechanisms ?
  • No leader
  • No preexisting tracks
  • High sensitivity to heterogeneities
  • Based on the nearest neighbor perception

30
Activation-inhibition mechanism
autocatalyzis
Inspired by equations of reaction-diffusion
Turing 1949
inhibition
The activator autocatalyzes its own production,
and also activates the inhibitor. The inhibitor
disrupts the autocatalytic process. Meanwhile,
the two substances diffuse through the system at
different rates, with the inhibitor migrating
faster. The result local activation and
long-range inhibition
31
Activation-inhibition mechanism
  • Activation-inhibition and self-organization share
    a common mechanism
  • Starting point a homogeneous substrate
  • (lacking pattern)
  • Positive feedback
  • (short-range activation, autocatalyzes)
  • Negative feedback
  • (long-range inhibition)

32
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33
Pattern formation in colonies activity
  • Patterns resulting from the activity of a
    society of
  • social insects
  • Ants
  • Bees
  • Wasps
  • Termites
  • Mammalians
  • African Mole-rats
  • Humans

34
Pattern formation in colonies activity
  • Patterns resulting from the activity of a
    society of
  • social insects
  • Ant
  • Bees
  • Wasps
  • Termites
  • Mammalians
  • African Mole-rats
  • Humans

35
Pattern formation in colonies activity
  • Patterns resulting from the activity of a
    society of
  • social insects
  • Ant
  • Bees
  • Wasps
  • Termites
  • Mammalians
  • African Mole-rats
  • Humans

36
Attraction-repulsion mechanisms
  • Relations between Activation-inhibition
    mechanisms and attraction-repulsion mechanisms
  • They share a common mechanism
  • Starting point a homogeneous substrate (lacking
    or different pattern)
  • Positive feedback (local activation or attraction
    rate to aggregates size)
  • Negative feedback (long-range inhibition,
    depletion in individuals)

37
Self-Organization in Natural Systems
  • Definitions
  • Pattern formation
  • In living and non-living systems
  • Social systems
  • Sociality and gregarism
  • Cellular systems
  • Cells build animals
  • Properties of self-organized systems

38
How cells build the animal ?
  • From one cell to the next generation
  • From one cell to the thinking brain
  • Planed mechanisms
  • Expression of the genetic program
  • Scale changes
  • And long range communication
  • Self-organizing mechanisms
  • Reaction-diffusion (activation-inhibition)
  • Cells migrations (Aggregation-repulsion)

39
How cells build the animal ?
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential

40
How cells build the animal ?
Strict genetic program Complex triggering
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential

41
How cells build the animal ?
Amplification of a behaviour (metabolism)t
rigger cell environment
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential

42
How cells build the animal ?
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential

Contact Mechanical
Direct
Indirect
Secretion diffusion At different range and time
43
How cells build the animal ?
Nucleus (DNA)
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential
  • Cytoplasm
  • RNA
  • Proteins
  • toxins

Controled exchanges
Internal state, memoryof previous events
(environments)
44
How cells build the animal ?
  • Accidental changes in cell environment
  • Backward differentiation
  • Not all animals
  • Global communication (blood circulationand
    nervous system)
  • Not all cells
  • Wounds should respect
  • Gradients
  • Periods of sensibility
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential

45
How cells build the animal ?
  • Low dynamic STRUCTURES
  • High dynamic FUNCTIONING
  • Neural activity
  • Immune system answer
  • Cell proliferation
  • Cell differentiation
  • Cell communication
  • Cell memory
  • Regenerative potential

46
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47
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

48
Social Insects
  • Problem solving benefits include
  • Flexible
  • Robust
  • Decentralized
  • Self-Organized

49
Interrupt The Flow
50
The Path Thickens!
51
The New Shortest Path
52
Adapting to Environment Changes
53
Four Ingredients of Self Organization
  • Positive Feedback
  • Negative Feedback
  • Amplification of Fluctuations - randomness
  • Reliance on multiple interactions

54
WEB CLUSTERING
  • Why?
  • The size of the internet has doubling its size
    every year. Estimated 2.1 billion as of July 2001
  • Organizing and categorizing document is not
    scalable to the growth of internet.
  • Document clustering?
  • Is the operation of grouping similar document
    to classes that can be used to obtain an analysis
    of the content.
  • Ant clustering algorithm categorize web document
    to different interest domain.

55
Ant Colony Models for Data Clustering
  • Data clustering?
  • is the task that seek to identify groups of
    similar objects based on the value of their
    attributes.
  • Messor sancta ants collect and pile dead corpses
    to form cemeteries (Deneubourg et al. )

f fraction of items in the neighborhood of the
agent k1, k2 threshold constants
56
Ant Colony Models for Data Clustering
  • The model later extend by Lume Faieta to
    include distance function d, between data objects
    .
  • c is a cell, N(c) is the number of adjacent cells
    of c, alpha is constant

57
Experimental Results
  • t 0

58
Experimental Results
  • t 50,000

59
Experimental Results
  • t 200,000

60
Experimental Results
  • t 300,000
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