Abstract:
An artificial neural network-based system and method for determining desired concepts and relationships within a predefined field of endeavor, including a neural network portion, which neural network portion includes an artificial neural network that has been previously trained in accordance with a set of given training exemplars, a monitor portion associated with the neural network portion to observe the data outputs produced by the previously trained artificial neural network, and a perturbation portion for perturbing the neural network portion to effect changes, subject to design constraints of the artificial neural network that remain unperturbed, in the outputs produced by the neural network portion, the perturbation portion operable such that production of an output by the neural network portion thereafter effects a perturbation of the neural network portion by the perturbation portion, the monitor portion responsive to detection of the data outputs being produced by the previously trained neural network, whereby the system is operable to derive over a period of time a plurality of input/perturbation/output mapping relationships that differ from the input/perturbation/mapping relationships of the training exemplars.

Description:
This application is a continuation of U.S. application Ser. No. 08/910,290, filed Aug. 13, 1997, now U.S. Pat. No. 6,018,727 which was a division of U.S. application Ser. No. 08/323,238, filed Oct. 13, 1994, now U.S. Pat. No. 5,659,666. 
    
    
     The present invention relates to a system and process for simulating the internal imagery and additional mechanisms which together emulate creativity in the human mind. The system allows for the totally autonomous generation of new concepts, designs, music, processes, discovery, and problem solving using recent developments in the area of artificial neural network (ANN) technology. Several examples of the type of useful information that can be obtained using the present technology are set forth and described herein. The present system can be used to tailor machine responses thereby making computers less rigid in communicating with and interpreting the way a human responds to various stimuli. In a more generalized sense, the subject system supplies the equivalence of free-will and a continuous stream of consciousness through which the system may formulate novel concepts or plans of action or other useful information. 
     Prior to this invention, artificial neural network (ANN) emulations of biological systems were used for non-creative tasks such as pattern recognition, neural control, and the generalization of experimental data. The present system represents a new approach and a new application of ANN&#39;s in which the system synthesizes novel plans of action and original designs or creations. These systems, which we refer to as autonomous systems or “creativity machines” may perform imaginative feats that extend beyond technological invention into the realms of aesthetics and emotions. 
     The present preferred embodiment of the system employs two essential components, namely, (1) a neural network containing training in some problem domain, which neural network is subjected to perturbations and, as a result of the perturbations, continuously outputs a stream of concepts, and (2) a monitoring portion, such as, in one particular preferred form, a second or patrolling neural network, which portion constantly monitors the outputs of the first network for various reasons, such as to identify and isolate useful outputs. This tandem arrangement may be thought of as constituting a model of creativity, and perhaps attentional consciousness, and this internal imagery is spontaneously generated within the perturbed network, while the monitoring portion is constantly alert to the occurrence of certain outputs, such as specific images possessing either utility or other useful characteristics including aesthetic appeal. The perturbations used may be achieved by any number of different means including by the introduction of noise, relaxation or degradation of the network and so forth. The two components discussed above will be described in more detail hereinafter. 
     It is important to emphasize that the present systems need not necessarily accept external information. Instead, the system may be allowed to operate such that information emerges spontaneously as a result of any number of stochastic and/or systematic processes applied to the characterizing parameters of the networks involved. With this tandem arrangement of the free-running neural network and the associated monitoring or policing portion, it is possible to generate a notion that is superior in quality to anything generated by a known system, device or machine similarly exposed or perturbed. 
     DISCUSSION OF THE PRIOR ART 
     The inventor has demonstrated that the application of certain types of noise to the inputs or weights of an ANN may produce novel outputs if the vector completion process fails to activate an output vector encountered during the network&#39;s training. Such outputs generally take the form of a combination of known training outputs and generally emulate the environment in which it was trained. Therefore, a neural network trained to generate the surface profiles of some device or object such as a known mountain range would tend to produce very plausible but unfamiliar mountain ranges if the inputs are subjected to random stimulations. Similarly, a neural network trained to only produce classical music would tend to produce potential classical themes when exposed to random inputs. The inventor has shown that static networks have produced some very novel outputs which have been detected within mathematical studies. In all known cases, however, they have been isolated by a human operator for their novelty. In contrast, the present system autonomously monitors the output of such a network and can operate to identify correspondences with or differences from predetermined criteria associated with the monitoring portion for various purposes, such as, in a preferred embodiment, to select emergent concepts, which may include courses of action, and which are representative of activation patterns of neurons, on the basis of some predetermined criteria established within a policing or patrolling neural network which, in such embodiment, is the monitoring portion of the system. Such concepts may include producing music or musical themes for some purpose, or for designing some device such as a coffee mug, or producing a process planning operation, or solving a problem, such as to seek a target figure of merit in a target seeking application of the system, and for many other applications, some of which will be described more in detail hereinafter. 
     Known ANNs have obtained a relatively high degree of precision in some areas such as in input-output mapping. The present invention teaches the use of deliberate degradation of an ANN and therefore a corruption of such precise mapping to produce useful information. Thus a network trained to duplicate some knowledge domain may generate fairly representative examples of known devices at low levels of network degradation. For example, in the case of automobile design the known networks may generate fairly representative examples of existing cars at low levels of network degradation owing to the constraints existing within the network. In other words sensible designs are produced. At progressively higher levels of network degradation, such network constraints further relax to produce novel and more unusual hybrid automobile designs, some of which may fill a useful application niche or market. The key to making the transition from the ordinary to the novel is achieved by the control over the network degradation and the ability to relax or perturb certain network parameters from their trained-in values. Thus the present system provides a way to design around the ordinary or the near ordinary and to create new designs in much the same manner as a creative designer would do, unlimited by certain constraints. As a result of the introduction of various forms of perturbations to the inputs, internal activations, weights and biases, such known systems may control a process or create an object or design. The information thus produced with the present system may be stored for later use to control a process or the like and/or used in its own autonomous decisions to modify the output or outputs that have been produced in some desired fashion. Thus the present system provides another tool, and a very broad based tool, for doing design or creative work, including as part of target seeking applications, through utilization of the two elements discussed above. It is contemplated, however, to fine-tune or toggle the subject system to autonomously change its mode of operation from performing one task to performing a different task or different purpose. 
     Being able to internally modify the network in a myriad of ways allows for vast numerical superiority in the number of viable concepts that may be produced. The present tandem arrangement of system elements allows for complete autonomy in this task. 
     OBJECTS OF THE INVENTION 
     It is a principal object of the invention to teach the construction and operation of novel means for simulating creativity. 
     Another object is to perturb artificial neural networks, previously trained, in order to produce useful and imaginative output information. 
     Another object is to monitor output information from a perturbed neural network in order to select desired outputs and reject others. 
     Another object is to produce controllable changes in a neural network by controlling the extent of perturbations applied thereto. 
     These and other objects and advantages of the present invention will become apparent after considering the following detailed specification of preferred embodiments in conjunction with the accompanying drawings wherein: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a system that depicts a system portion entitled imagination engine (IE) in association with another system portion entitled alert associative center (AAC) connected to operate according to the teachings of the present invention; 
     FIG. 2 illustrates how perturbations from an external source are applied to a particular embodiment of the present system to produce a plurality of outputs any one or more of which can be selected to represent the desired output information (mode A); 
     FIG. 3 illustrates how perturbations in the form of connection weight pruning can be applied to the system of FIG. 2 to produce a plurality of outputs any one or more of which can be selected to represent the desired output information (mode B); 
     FIG. 4 illustrates how perturbations in the form of connection weight prunings can be applied to a recurrent network to produce a plurality of outputs which can be selected to represent a novel procedure (mode C); 
     FIG. 5 is a diagram of one embodiment of the subject system used in designing and/or producing a desired shape for a coffee mug; 
     FIG. 6 is a block diagram of the means employed to produce the coffee mug of FIG. 5; 
     FIG. 7 is a view showing one form of the operating members controlled by the subject system in the production of the desired shape for a coffee mug; 
     FIG. 8 shows examples of acceptable and unacceptable coffee mug designs; 
     FIG. 9 depicts an embodiment of the subject system, illustrating the manner in which the inputs and outputs of the subject system can be used for producing musical verses utilizing a recurrent network; 
     FIGS. 10A-10C illustrate network activations employed in the production of acceptable music where the training produces a combination of the songs “TWINKLE, TWINKLE LITTLE STAR”, “DAISY” and “MARY HAD A LITTLE LAMB”; 
     FIG. 11 shows a manner in which the subject system can be employed to convert the outputs of the IE of FIG. 10A to sounds; 
     FIG. 12 shows ten (10) musical phrases produced by the system embodiment depicted in FIG. 9; 
     FIG. 13 depicts an embodiment of the subject system, illustrating a manner in which the inputs and outputs of the subject system can be used for producing musical phrases utilizing a simple feed forward network and perturbations applied to both inputs and connection weights of that network; 
     FIGS. 14A and 14B show musical phrases of acceptable form produced using a non-recurrent feed forward network; 
     FIGS. 15 a-   15   b  show fifty (50) novel musical themes or phrases produced by the system of FIG. 13; 
     FIG. 16 depicts an embodiment of the subject system, illustrating a manner in which the inputs and outputs produced by such embodiment can be used for producing novel automobile designs; and 
     FIGS. 17A and 17B show two automobile designs produced by the system of FIG. 16, including a design (1) to achieve at least 35 PMG, cost less than $25,000.00 and have a favorable rating in terms of user satisfaction and design (2) which is an automobile capable of accelerating to 60 MPH in less than eight (8) seconds and achieve a top speed of at least 150 MPH. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings more particularly by reference numbers, number  20  in FIG. 1 refers to a preferred system constructed according to the present invention. The system  20  includes two basic components, one labeled imagination engine (IE)  22 , which is an artificial neural network (ANN) that is subjected to perturbations, sometimes in a progressive manner, as will be discussed further hereinafter, while producing outputs which it feeds to a second, monitoring component, comprising what is hereafter generally referred to as an alert associative center (AAC)  24 , which component is a system portion that monitors the IE  22  and which, in some preferred embodiments, may also be an artificial neural network, and which, in turn, may have one or more feed back connections  28  to the IE  22 . The IE or imagination engine constitutes that portion of the subject system that receives the input information in the form usually of stochastic noise or perturbations applied against the training of the IE and is applied to its weights, biases, inputs, outputs or internal activations. The imagination engine is so described in order to convey the idea that this network is perturbed either internally or externally, and as a result of attempting to perform pattern completion in the presence of the perturbations or noise, produces outputs which freely wander through some given knowledge domain which is embodied in the network&#39;s training. The outputs can also be recycled. The outputs of the IE are monitored or patrolled by the AAC. The IEs and the AACs may be grouped or coupled into one or more of a plurality of relationships depending upon what is to be accomplished and the nature of the inputs and outputs that are required. The IE and AAC can be combined into more complex systems involving a plurality of coupled ANNs and is able to perform more involved tasks including problems that require a certain degree of creativity, as will be further addressed hereinafter with regard to FIG.  16 . 
     It has been discovered that it is common to all neural networks that whenever a neural network is subjected to a synaptic perturbation process wherein connection strengths between neurons are progressively altered, such a process activates the memories of the environmental features the network has already seen or been trained in. Thereafter, as the network continues to evolve from its initial trained state, such environmental features are combined into hybridized or juxtaposed features. For example, a neural network trained to produced the images of various animals, including those of a cow and a bird, would first produce random, intact images of these animals and birds during low levels of synaptic perturbation. Progressively stronger perturbations in synaptic connection strength would now produce hybridized images, including that of a flying cow, something that is part cow, part bird and so forth. In other words, the same universe embodied within the IE has begun to unravel as constraints are gradually removed and new, unheard of combinations emerge. By the same token, intact neural networks, either artificial or biological, may be activated to produce novel environmental images by noise or other processes occurring externally to themselves. Such noise may be generated by the function, relaxation or degradation of other surrounding networks and communicating biological networks or complex network implementations. The results will be similar to that when using internally generated perturbations, with a spontaneous appearance of both straight forward as well as hybridized environmental features. 
     This can also be accomplished by constructing the IE of a plurality of neurons so that some portion of the processing units remains unrecruited to the required training or mapping. Application of any of the perturbing influences to these uncommitted neurons can produce significantly increased generation of useful concepts, which can in turn be captured or processed or selected by the AAC. The AAC, which is the second major component of the subject system as depicted in FIG. 1, forms all or part of a monitor portion that operates in some of the preferred embodiments, as will be discussed in greater detail hereinafter, to monitor and identify useful information or juxtapositions produced by the IE. The monitor portion or AAC is therefore an opportunistic component that is on the lookout for certain features or conditions, such as correspondences with or deviations from established criteria, which, in our present example, would entail looking out for particular animals or the like. In a typical situation, the AAC can be designed or trained to assign numerical or other scores to the hybrids or results synthesized by the IE. One or more separate algorithms can form or be associated with the AAC for such purposes and to store potentially useful concepts for later consideration and refinement, or alternatively can be used to immediately influence results in a hardware condition. In many of the more detailed embodiments depicted and discussed herein, the AAC is, like the IE, also selected to be an ANN, which has been trained to identify useful information or juxtapositions produced by the IE and which can also be trained to assign numerical values to the hybrids synthesized by the IE. In some embodiments it is also contemplated that some of the inputs to the AAC may not be connected to outputs of the IE but may be left free for other purposes. In this way the AAC selection criteria can be adjusted initially or during operation for example as shown in FIG.  3 . 
     Three different modes of operation for the combined IE and AAC neural network object (which combination can encompass various degrees or levels of distinction and/or integration of the IE and AAC when both are neural network objects) will be discussed hereinafter. These modes can be used separately or in various combinations. These are described as modes A, B and C. In mode A, any number of techniques, including random number generation, may be used to supply novel inputs to the IE. This results in the IE attempting vector completion on the novel inputs, usually resulting in some change or juxtaposition of its established training outputs. The AAC then checks the utility of these resulting hybridized outputs from the IE and assigns values to select criteria shown as A-Z in FIG.  2 . When the selection criteria are met, the hybridized output may then be immediately utilized or recorded for later use. 
     In mode B, fixed values are clamped to the inputs of the IE while its weights, biases, or internal activations are perturbed by any number of numerical techniques, including random number generation to perturb them from their original values. An internal completion process within the network layers produces new conditions or juxtapositional concepts which emerge at the outputs of the IE. The AAC then rates these in terms of their usefulness based on its own training. As in mode A, these new concepts may be utilized in real time as the network relaxes or they may be saved in an archival file for later use. 
     In mode C, the IE perturbation is used to create a plan of action or a procedure to solve a given problem. An example of such a system is shown in FIG.  4 . In this example the IE feeds its own outputs back to its respective inputs and the procedure consists of a sequence of steps, each of which is contingent upon the prior step. In mode C, the AAC examines each step to assure its utility in forming an allowable and useful step in arriving at the desired result. Also in mode C, the AAC may be used to modify the architecture of the IE at any stage, for instance, by the removal, modification, or replacement of any given weight or step. In mode C, an algorithm governing the operation could have weights randomly chosen within the IE and set to constant values, for example zero. The AAC would then evaluate the system configuration for its utility or other purpose. If the evaluated state is not an allowable one, the AAC would make the decision to replace the temporarily removed weight and inform the driving algorithm to select a new weight for removal. Once the desired system configuration is obtained, the system begins to remove more weights from the IE. The AAC is alert to whether the overall target configuration was obtained. If it was, the algorithm stores the successful sequence of operation which constitutes a procedure or it would immediately convey this information to control some external device or hardware mechanism. In this way an ANN serving as the IE assists, in a manner somewhat similar to the way the human brain works, storing a concept or idea using a computer or the like. This can be done in the present system by having a human participant or the machine user produce feed backs to the IE in which different perturbations are applied to the IE network for some purpose such as to boost or change its outputs. By using multiple IEs and AACs more complex outputs can be obtained and in some cases more accurate and precise data can be produced. For example, many separate networks of this type can be used in the concept selection process thereby necessitating the use of many different AACs. 
     In any of the above modes or juxtapositions any combination of perturbing factors can be used to generate novel concepts within the IE. Such perturbations may combine different factors such as (a) weights, (b) biases, (c) activations, (d) external input signals, (e) internal input signals to any given unit within the network, or (f) internal output signals from any given unit within the network. In like manner the parameters a-f may be perturbed by various means such as by (1) successively setting their values to some constant value such as zero; (2) successively adding some random number as obtained with a random number table to their original values; (3) successively changing their values by replacing them with random numbers obtained from a random number table; (4) multiplying their values by a time-dependent factor usually with some decay constant; (5) successively adding positive and negative random numbers obtained through a random number table to allow these parameters to perform a random walk about the original values; (6) adding numbers which obey certain statistical frequency distributions of the form where the probability of choosing such a number obeys a probability function; (7) adding numbers which obey set time-dependent statistical distributions; and/or (8) progressively multiplying any of the above factors by some gradually increasing amplitude factor so as to smoothly transition the IE from its original constrained condition, implicit within its training, to progressively relax constraints as the weights and biases stray from their training values. It has been found that enhanced results may be obtained by specifically applying such perturbating influences to neurons which have not been fully recruited into the network&#39;s mapping or training. 
     In partial summary, an autonomous search procedure to arrive at novel concepts has been described, and such a search procedure is applicable to different knowledge domains. The novel outputs or problem solutions are arrived at through the interaction of two components: a first ANN, oftentimes referred to herein as an IE, and an associated monitor portion, oftentimes referred to herein as, or including, an AAC, which monitors the outputs of the first ANN and which can also itself take the form of or include an ANN in various particular embodiments, as will be discussed in greater detail hereinafter. The first neural network is trained to produce outputs within the knowledge domain of its training, as a consequence of which input-output mapping is produced that models a particular problem. One can then seek a given pattern in the output from such neural network by applying perturbations to such neural network until the desired pattern in the output is produced. The introduction of such perturbations to any number of ANN features causes the first neural network to wander through the knowledge domain producing meaningful outputs under the constraints of its connection strengths and biases. As the level of the network perturbations increases, the constraints begin to more dramatically relax from their trained-in values and unconventional conceptual juxtapositions emerge which can be detected and utilized by the monitor portion to alert an associative center or output device, such as when a targeted figure of merit is obtained or a desired output pattern is realized. The major strength of this technique is its ability to gradually and systematically perturb the IE network from a state in which it simply duplicates known features of its knowledge within its knowledge domain to a subsequent state of perturbation in which ever so slightly new juxtapositional or hybridized concepts emerge. The subtle changes from the conventional to the mildly unconventional produce new and potentially useful inventions which can be autonomously identified and selected by the monitor portion. Thus the present system limits its search space in seeking solutions to many different problems and it does so in a unique manner. 
     Coffee Mug Design 
     Referring now to FIGS. 5-8 there is shown a particular embodiment of the subject system that can be used in the design and production of devices such as a novel coffee mug and the like. The subject coffee mug can be aesthetically pleasing and also serve a useful function. It is apparent, however, that the subject system is not limited to the production of coffee mugs and can be used to produce many other designs and shapes including works of art. It is also possible to interface the subject system with a lathe, stereo lithographic, or other operating device including a potter&#39;s wheel to cause the subject system to produce in a three dimensional form, the object in question, in this case a coffee mug. In FIG. 5 the subject system embodiment  20  is illustrated on the right hand side and a potter&#39;s wheel  47  with a mound of clay  46  mounted on it is shown on the left side. Also shown in FIG. 5, in illustrative form, is a device or operator member  48  which operates against the lump of clay  46  to form the coffee mug into the desired shaped. The controls for the shaping means  48  are produced by the output of the IE  22  as selected by the beauty and function outputs which signal the controlling algorithm to apply the IE outputs. 
     FIG. 6 is a logic flow diagram of the means shown in FIG.  5 . The diagram includes the IE  22 , the AAC  24 , which, in this embodiment, is also an ANN, an output decision block  52  which has a NO output flowing back to the IE on  58  and a YES output  54  labeled Implement Design which is led back at  56  to the IE. The block  52  is labeled Does IE Output Exceed Thresholds? The YES output  54  controls devices such as a template or movable pins or the like in such a manner as to form the shape of the mug. 
     FIG. 7 illustrates how the outputs of the various portions of the IE  22  are used to control, in this case, solenoids  48  which have means that engage the body of clay  46  to produce the desired shape. The solenoids  62  are parts of the assembly  48  and are shown operated by spring tension produced by springs  60  and offset by the magnetic force generated by the electrical currents proportional to the IE outputs. 
     FIG. 8 shows various coffee mug designs, including some which are aesthetically pleasing and utilitarian, and others which have minimal utility values. The cup designs are labeled  46 A- 46 L. 
     In designing a coffee mug, various options should be assembled as to the aesthetic and utilitarian preferences and this information should be encoded in the AAC. This can be done using a computer code which generates vertically aligned stripes of various lengths which together stimulate the profile or potential mug design. These designs can be displayed on a cathode ray tube or the like using stripes of random lengths and widths and opinions can be gathered as to beauty and utility using ranking scores. The information thus obtained can be put on a spread sheet to be used for training the two separate neural networks, the IE and the AAC of this particular embodiment. The IE is trained using beauty and utility as the inputs and the AAC reverses the significance of the inputs and outputs so that the shape now serves as inputs and beauty/utility ratings and these become the outputs. 
     Music 
     FIGS. 9-14 and  15   a-   15   b  illustrate another embodiment  70  of the subject system being used to produce musical compositions or musical phrases. Referring to FIG. 9, the embodiment  70  includes an IE  72  and an AAC  74  shown coupled together as in the previous constructions. The AAC is trained to select from among the various outputs of the IE and to produce an output musical rating at block  76 , which rating is applied to a block  78  which is labeled Rating Exceeds Threshold? If the rating does not exceed the threshold then an output will be produced on lead  80  which is applied to a block labeled Disregard New Note  82 , and this output is applied to other blocks including block  84  labeled Refresh Weights and block  86  labeled Perform Random Weight Prunings and fed back to the IE on lead  90 . If the output of the block  78  is YES then outputs will be produced through the block  88  labeled Add New Note To The Buffer for applying back to the IE to further modify the condition of the IE. The difference between FIG. 9 and the design previously discussed in connection with the production of a coffee mug is that in FIG. 9 the outputs are musical tones or the like arranged in a particular manner depending upon the training of the IE and the AAC, and the outputs are musical phrases or themes as will be explained. In the production of musical compositions or themes the present embodiment employs a similar relaxation technique that embodies modes A, B and C, as discussed above, and in so doing achieves a meaningful synthesis of the original musical themes. The IE in this embodiment is a recurrent network which learns to perform a number of songs such as “TWINKLE, TWINKLE LITTLE STAR”, “DAISY” and “MARY HAD A LITTLE LAMB”. The network as shown utilizes an 8-10-8 architecture as shown in FIG. 9, with the outputs of the network fed back as inputs. The first two inputs encode song (S 1 ), (S 2 ), the next four (N 1 -N 4 ) signify note order and the last two (FI, DI) contain the pitch and duration of any given note. The outputs of the network take on similar significances with all the values taking on appropriate values for the next note within the musical sequence. The network as shown in FIG. 10A has four layers ( 1 - 4 ), denoted (L 1 -L 4 ). The outputs of the network attain the same significance but now represent the next note in the sequence. There are two hidden layers of neurons each necessary to achieve the desired mapping. This is shown in FIG. 10A by the two middle rows of neurons. By setting the left most inputs S 1 -S 2  to values of (0,1), (1,0) or (1,1), the recurrent network would play “TWINKLE, TWINKLE LITTLE STAR”, “DAISY” and “MARY”, respectively. The application of random numbers to all of the inputs of the networks and in particular to S 1  and S 2  would cause the network to jump from one song to another song thereby juxtaposing tunes and producing music. 
     Referring again to FIG. 10 there is shown (1) network activation in the form of individual neurons shrinking and expanding according to different levels of activation, (2) a strip chart recording the most recent train of notes including their pitches, and (3) the output of a separate network which has been trained to classify the output of the concurrent network as a linear combination of any of the three training melodies. This latter feature is helpful in envisioning the weighting of individual tunes within the hybridized songs. Such musical hybridization is occurring in FIG. 10 where we see a combination of “TWINKLE” and “MARY” having been selected by the AAC and being performed. Training of the IE is accomplished by creating the map between successive notes within any particular song. As inputs the circuit is provided with binary coded labels for the song number. For example, binary coded song numbers  1 - 3  are input to nodes S 1  and S 2 , binary coded note order  1 - 31  are input to nodes N 1 -N 4  and frequency and duration values are input to nodes F 1  and D 1 . The targets for training include identical binary coded song number (output notes S 1  and S 2 ), binary coded note order incremented by a value of 1 (output nodes N 1 -N 4 ) and the next frequency-duration pair of the song in output nodes F 1  and D 1 . Wrap-around of the songs is achieved by mapping the last note in the musical sequence to the first. What has just been described refers to the operation of the IE. It is now necessary to describe the function and training of the AAC which operates on the output from the IE. For training purposes a training computer code is written to generate a series of 4 notes, consisting of a series of notes which obey a 1/f distribution, a feature which is characteristic of all sounds we accept as music. This series of tones is subjected to an evaluation after which human evaluators were asked to respond on a 0-10 point scale to its aesthetic value. After about 100 trials of this sort, the series of frequencies comprising each melody was passed to a spread sheet along with their consensus rankings. Inputs therefore consisted of the note sequences along with target values for training consisting of the numerical scores. Real melodies were implanted within the training set and ranked at values of 10 for their appeal. Noise on the other hand from a random generator was embedded within the spread sheet with ranking values of 0. Following training on this data, the trained neural network IE and AAC were embedded within the same computer code. 
     The IE was placed within a loop wherein values between zero and 1 were fed to its inputs from a random number generator thus producing or generating composite melodies at the IE&#39;s outputs. A buffer containing at most four notes (4 frequency-duration pairs) played at anytime was sampled by the eight inputs of the AAC, rating each according to its musical acceptability. The best musical themes, those exceeding a threshold of 8 on the 10 point scale were played and archived to a separate file. Generation of music composed by the subject machine was achieved by the scheme shown in FIG.  11 . Outputs from the IE deemed acceptable by the AAC are serially transmitted as a series of sound commands involving both frequency and duration of successive notes to the computer. These total commands are translated from digital to analog signals and fed to a loud speaker where the sounds can be heard. Therefore as the subject machine generates acceptable note sequences, it instantaneously relays them to an audio output device so that the operator of the machine can hear the music that has been produced. The next 4 notes generated by the IE were similarly added to the buffer and played, and so on. Ten samples of these melodies captured by the AAC are displayed in FIG.  12 . Their frequencies F are shown in Hz (1 octave being shown), while the duration D of each note is given in units of {fraction (1/18)} of a second. The combination of frequency and duration produce sound. 
     A second approach to synthesizing original music involves using the subject embodiment modified to consist of an IE of 3-16-20 nodal architecture and an AAC of 20-10-1 nodal architecture. The former produced a note sequence consisting of musical phrases or themes. Subsequently, the AAC checks this trial melodic phrase for its musical acceptability. This is shown in FIG.  13 . In this case the IE is trained to perform pattern completion on the tonal frequencies (i.e., in Hz) of the first three notes within a given musical phrase. The musical phrases for training consist of very recognizable segments from twenty well known songs. Thus given the first three notes, the network was trained to supply the remainder of that musical sequence. The output consisted of ten successive frequency-duration pairs with the frequency given in Hertz and the duration in units of {fraction (1/18)} second. 
     In the same embodiment the AAC is trained by exposure to twenty ten note segments from popular melodic themes, 50 examples of tones generated from frequencies selected from a random number table and about 100 trial melodies generated by the introduction of noise into a similar IE trained only on noise and the above popular melodic themes. Target values for training consisted of numerical scores of 1 for the popular themes, numerical rankings of 0-1 on the IE generated melodies (as determined by human panelists,) and numerical scores of 0 for noise generated using a random number table. 
     Using various combinations of IE prunings, introduction of both time-varying inputs and time-varying perturbations to the internal connection weights of the IE enabled the subject creativity machine to run autonomously until 11,000 musically acceptable themes or phrases had been collected. Typical musical phrases created by this process are shown in FIG.  14 . In FIGS. 15 a-   15   b  fifty representative musical phrases produced by the subject embodiment are shown. At the top of the listing are identifiers as to the frequency and duration for the numbers shown in each row. In other words, FIGS. 15 a-   15   b  show a number of musical themes audibly reproducible wherein the frequency and duration of each tone is indicated. 
     Automobile Design 
     Another application of an embodiment of the subject system demonstrates modes A and B wherein the AAC is allowed to make autonomous decisions to modify the architecture of the IE as well as to hold certain inputs to the IE constant. The intent of this example is to design an automobile or car in terms of its major specifications and characteristics. This is done based on some notions as to its desired performance, insurance coverage, warranties, probability of theft, and anticipated user satisfaction. In creating the subject embodiment, 29 performance characteristics of the design specification are shown as possible inputs to the IE in FIG.  16 . The AAC, on the other hand, which, in this embodiment is also an ANN, reverse maps from the design specifications to performance characteristic. Both networks IE and AAC utilize a 29-10-29 nodal architecture. The structure  100  shown in FIG. 16 includes an IE  102 , an AAC  104 , and an output  106  from the AAC which flows into a decision block  108  that bears the legend Does Candidate Auto Design Meet Performance Criteria? The block  108  has a YES output  110  which flows to an archive design block  112  which in turn flows back to the input of the device  100  through branch  116 . The output of the block  108  also flows back to the input of the device  100  via branches  118  and  116 . The branch  116  flows to the input of the IE  102  by a block  120  labeled Apply Perturbations to IE connection weight which provides the perturbations to IE  102 . The block  120  also flows to another block  122  labeled “Search Continued For More Than N Cycles?” which has an output  124  that flows to block  126  labeled Skeletonize IE which are applied as inputs to the IE  102  and also has an output which flows to the input block labeled Input Random Performance Factors to IE. The block  124  has another output which flows through branch  130  to the same Input Random Performance Factor block to inputs of the IE  102 . 
     It will be appreciated that, in this particular embodiment, since the AAC is also an ANN, and since the block  108  operates to examine the output of the AAC and to determine whether the output performance data therefrom satisfies desired performance criteria, block  108  functions as a monitor portion for a system that includes the ANN of AAC  104 , which may be thus be considered the IE of such system, and AAC  104  can also be viewed as part of the monitor portion for another system that includes the ANN of IE  102 . Such particular embodiment is thus illustrative of one manner in which a more complex system utilizing a plurality of the subject ANN systems can be realized. 
     In operation, the IE inputs are fed values from a random number table. As each of these 29 component vectors are propagated through the network, physically realizable automobile designs appear at its outputs, prescribed in terms of its 29 design specifications. Each set of outputs from the IE is then fed to the AAC  104  inputs wherein feed forward propagation produces the performance characteristics which would result from that particular set of specifications. These performance characteristics are then compared with those desired to determine whether or not the appropriate design has been obtained. This is what is trained into the AAC. If the design characteristics meet the criteria, the car design is displayed on some means such as a cathode ray tube. If the design does not meet these requirements, additional random inputs are fed to the IE  102  and new pertubuations are applied to the IE connection weighhts to generate another candidate design to be evaluated in like fashion by the AAC  104 . FIG. 17 shows the design of a car possessing a highway mileage of at least 30 MPG, a retail price of at most $25,000 and a projected user satisfaction of one on a (1), 0, (−1) rating scale that has been synthesized by the subject embodiment. 
     It is important to note that the network in this case is producing only physically realizable car designs by carrying out vector completion on the input vector consisting of random components as well as internal pertubations applied to the IE. Also, in this example, properties such as curb weights and tire size are realistically scaled with factors such as horsepower. Thus myriad nonsensical specifications are eliminated within the IE via the soft constraints offered by the connection strengths within the trained neural network. If the subject embodiment is given numerous performance criteria search time will be extended. Therefore, if after a predetermined number of forward propagations such as ten propagations through the IE  102 , the performance criteria have not been met, the algorithm would direct the controlled pruning of weights from the IE  102  in an attempt to narrow the search down. In this case, weights are removed one by one from the IE, while propagating a number of randomized input vectors through the entire device  100  to see if the AAC output falls within a predetermined envelope of performance values that blanket the desired range. Should a weight be removed which generates AAC outputs outside this range, it is replaced. Should a more radical automobile design be required, systematic increase of the amplitude of the perturbations applied to the connection weights of the IE would be made, depending upon the AAC to predict the performance of such hypothetical automobiles. 
     It will be obvious to those skilled in the art that the present invention can be used for many purposes other than the limited purposes described herein. The important thing to recognize is that by using an IE and an associated monitor portion (AAC), especially when the IE and the AAC are comprised of two neural networks or groups of neural networks, one of which operates as the IE and the other as the AAC, it is possible to envision myriad possible uses therefor. These uses can be in designing, problem solving, selecting, developing manufacturing processes and many other areas. 
     Thus there has been shown and described a novel system which simulates creativity and autonomously generates useful information for some purpose. Many changes, modifications, variations and other uses in applications for the subject system will suggest themselves, to those familiar with the art. All such changes, modifications, variations and other uses in applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.