Friday, June 25, 2010
Sunday, May 9, 2010
Christopher deCharms looks inside the brain
Neuroscientist and inventor Christopher deCharms demonstrates a new way to use fMRI to show brain activity -- thoughts, emotions, pain -- while it is happening. In other words, you can actually see how you feel.
Monday, February 22, 2010
Data Structures and Algorithms
Data Structures and Algorithms
I found this website which contains various animations of the algorithms covered in a typical data structures course. In addition to providing the code it also highlights which particular lines are active during the animation.
Examples:
In addition, complexity analysis of algroithms are also included. The following postscript contains the explanation as well as the mathematics underlying the process of the analysis. Also on page 4 are examples of actual algorithms and the analysis process.
Complexity
The codes are written in Java. I'm not sure how many people are familiar with Java but figured I might post some key concepts.
Example:
The "void" component declares that the method will not be returning anything. Usually this declaration is used when instance variables are being modified. Another declaration would be to declare the variable being returned. An example would be public int[] buildHeap(int[] a). This would essentially declare that the method buildHeap will return an array of contents integer data types with an integer array data type as its paramater with variable name "a".
The "int[] a" component declares that the paramater being sent to the method is an array containing the integer data type for its contents. The "a" component declares the variable name, similar to def methodName(self,a) in python.
The for loop is declaring that the integer i is being decremented by 1 from initial condition of the length of a/2 to i<=0. In other words, running only while the condition i>0 is true.
I found this website which contains various animations of the algorithms covered in a typical data structures course. In addition to providing the code it also highlights which particular lines are active during the animation.
Examples:
In addition, complexity analysis of algroithms are also included. The following postscript contains the explanation as well as the mathematics underlying the process of the analysis. Also on page 4 are examples of actual algorithms and the analysis process.
Complexity
The codes are written in Java. I'm not sure how many people are familiar with Java but figured I might post some key concepts.
Example:
public void buildHeap(int[] a) {The "public" component declares that the method will be publically acessible to outside classes. Another declaration would be "private" which would be similar to def __methodName(self,a) in python.
for (int i = a.length/2; i>0; i--) {
heapify(a,i);
}
}
The "void" component declares that the method will not be returning anything. Usually this declaration is used when instance variables are being modified. Another declaration would be to declare the variable being returned. An example would be public int[] buildHeap(int[] a). This would essentially declare that the method buildHeap will return an array of contents integer data types with an integer array data type as its paramater with variable name "a".
The "int[] a" component declares that the paramater being sent to the method is an array containing the integer data type for its contents. The "a" component declares the variable name, similar to def methodName(self,a) in python.
The for loop is declaring that the integer i is being decremented by 1 from initial condition of the length of a/2 to i<=0. In other words, running only while the condition i>0 is true.
Monday, February 1, 2010
Advanced Biological Computers
Are you familiar with the movie eXistenZ? Though it was primarily a movie designed as a thought experiment to the implications of VR, it offered one very interesting possibility - advanced biological computers. Neurons already reorganize on their own during early development and even in adulthood. What's stopping us from utilizing this technique in hardware? The notion is similar to programming all the GUI components in Java when IDEs (e.g NetBean) already offer visual GUI component creation. We seek chips which may alter themselves, yet biology is already there.
We're already capable of using electrodes to analyze and transmit data to and from the brain. There's also software that models the brain to such accuracies that people base their research almost entirely off of the firings simulated by it (Neuron).
Links
Algae and Light Help Injured Mice Walk Again.
DNA Computers
Computer vs bacteria
We're already capable of using electrodes to analyze and transmit data to and from the brain. There's also software that models the brain to such accuracies that people base their research almost entirely off of the firings simulated by it (Neuron).
Links
Algae and Light Help Injured Mice Walk Again.
DNA Computers
Computer vs bacteria
Non-Anthropocentric Personhood Ethics
Non-anthropocentric personhood ethics is a system of rights based on the qualities of personhood rather than on "humanness". In contrast to the human-racist positions of bioconservatives, technoprogressives adopt a non-anthropocentric system of ethics in order to accommodate non-humans ranging from animals, such as Great Apes, to future post-humans and their cognitive equivalents such as artificial intelligences.
Non-anthropocentric personhood ethics does not assign value to embryos or the brain dead on the basis that they are human. Instead, it values the humans who are alive and actually persons. Additionally, non-anthropocentric ethics extends varying degrees of personhood to non-human entities on the basis of intellectual complexity. Thus, great apes and dolphins for instance would receive some rough moral parity with humans.
From: http://ieet.org/index.php/tpwiki/Non-anthropocentric_personhood_ethics/
Non-anthropocentric personhood ethics does not assign value to embryos or the brain dead on the basis that they are human. Instead, it values the humans who are alive and actually persons. Additionally, non-anthropocentric ethics extends varying degrees of personhood to non-human entities on the basis of intellectual complexity. Thus, great apes and dolphins for instance would receive some rough moral parity with humans.
From: http://ieet.org/index.php/tpwiki/Non-anthropocentric_personhood_ethics/
Artificial Muscles
Current artificial muscle devices are made from air pumps:
http://www.youtube.com/watch?v=iNgdqOLtUZY&feature=related
But new technologies will eventually make artificial muscles smaller and even more powerful than normal ones. Here are some man-made actuator technologies that are the most promising for future developments of artificial muscle:
Electromagnetic Actuators – are specially designed electromagnets that consist of a coil and a movable iron core called the armature. When current flows through a wire, a magnetic field is set up around the wire. When the coil of the solenoid is energized with current, the core moves to increase the flux linkage by closing the air gap between the cores. The movable core is usually spring-loaded to allow the core to retract when the current is switched off. The force generated is approximately proportional to the square of the current and inversely proportional to the square of the length of the air gap. Unlike hydraulic pistons, this actuator is totally silent and extremely smooth.
Piezoelectric Actuators – have a very high electric field corresponding to only tiny changes in the width of a piezo crystal, this width can be changed with better-than-micrometer precision, making piezo crystals the most important tool for positioning objects with extreme accuracy. There are two kinds of these actuators: direct piezo actuators and amplified piezo actuators.
Shape Memory Alloy – is an alloy that "remembers" its original, cold, forged shape, and which returns to that shape after being deformed by applying heat. This material is a lightweight, solid-state alternative to conventional actuators.
Magnetostrictive Actuators – are made from materials that exhibit a strain when exposed to a magnetic field. In other words, magnetostrictive materials undergo a deformation when a magnetic field is present. These materials are referred to as the Rare-Earth's. Rare-Earth materials typically consist of the lanthanides group in the transition metals on the periodic table.
Electrostatic Actuators – are comprised of parallel plate electrodes where one or both are being moved by an electrostatic coulomb force between them.
And the winner is:
Dielectric Elastomers – are electroactive polymers in which actuation is caused by electrostatic forces between two electrodes which squeeze the polymer. Dielectric elastomers are capable of very high strains and are fundamentally a capacitor that changes capacitance when voltage is applied by allowing the polymer to compress in thickness and expand in area due to the electric field. They have low power consumption and are considered to exhibit the closest behavior to natural muscle.
http://www.youtube.com/watch?v=Ga_IafGRWyE
http://www.youtube.com/wat
But new technologies will eventually make artificial muscles smaller and even more powerful than normal ones. Here are some man-made actuator technologies that are the most promising for future developments of artificial muscle:
Electromagnetic Actuators – are specially designed electromagnets that consist of a coil and a movable iron core called the armature. When current flows through a wire, a magnetic field is set up around the wire. When the coil of the solenoid is energized with current, the core moves to increase the flux linkage by closing the air gap between the cores. The movable core is usually spring-loaded to allow the core to retract when the current is switched off. The force generated is approximately proportional to the square of the current and inversely proportional to the square of the length of the air gap. Unlike hydraulic pistons, this actuator is totally silent and extremely smooth.
Piezoelectric Actuators – have a very high electric field corresponding to only tiny changes in the width of a piezo crystal, this width can be changed with better-than-micrometer precision, making piezo crystals the most important tool for positioning objects with extreme accuracy. There are two kinds of these actuators: direct piezo actuators and amplified piezo actuators.
Shape Memory Alloy – is an alloy that "remembers" its original, cold, forged shape, and which returns to that shape after being deformed by applying heat. This material is a lightweight, solid-state alternative to conventional actuators.
Magnetostrictive Actuators – are made from materials that exhibit a strain when exposed to a magnetic field. In other words, magnetostrictive materials undergo a deformation when a magnetic field is present. These materials are referred to as the Rare-Earth's. Rare-Earth materials typically consist of the lanthanides group in the transition metals on the periodic table.
Electrostatic Actuators – are comprised of parallel plate electrodes where one or both are being moved by an electrostatic coulomb force between them.
And the winner is:
Dielectric Elastomers – are electroactive polymers in which actuation is caused by electrostatic forces between two electrodes which squeeze the polymer. Dielectric elastomers are capable of very high strains and are fundamentally a capacitor that changes capacitance when voltage is applied by allowing the polymer to compress in thickness and expand in area due to the electric field. They have low power consumption and are considered to exhibit the closest behavior to natural muscle.
http://www.youtube.com/wat
3D Printers: Present and Future
Exciting news! Researchers at Organovo are promising to be able to print entire organs for transplant patients. That technology would certainly be the jewel in the crown of the 3-D printing industry, but is Organovo living up to the hype? See for yourself:
http://www.youtube.com/watch?v=80DhBLEhdzk
Now, plastic 3-D printing machines have been around for a few years, but I just thought this one was really cool since it’s the first of its kind to print in a few hours and in color!
http://www.youtube.com/watch?v=ps0WEZbDjHE
And now for the crème de la crème of the future of 3D printing, nanoassemblers! “A nanoassembler is a proposed system in which nanomachines (resembling molecular assemblers, or industrial robot arms) would combine molecules to build larger atomically precise parts. These, in turn, would be assembled by positioning mechanisms of assorted sizes to build macroscopic but still atomically-precise products. A functioning nanofactory could create virtually any product at the cost of only the input raw material and energy.” Could this ever become a reality, you decide:
http://www.youtube.com/watch?v=zqyZ9bFl_qg
http://www.youtube.com/wat
Now, plastic 3-D printing machines have been around for a few years, but I just thought this one was really cool since it’s the first of its kind to print in a few hours and in color!
http://www.youtube.com/wat
And now for the crème de la crème of the future of 3D printing, nanoassemblers! “A nanoassembler is a proposed system in which nanomachines (resembling molecular assemblers, or industrial robot arms) would combine molecules to build larger atomically precise parts. These, in turn, would be assembled by positioning mechanisms of assorted sizes to build macroscopic but still atomically-precise products. A functioning nanofactory could create virtually any product at the cost of only the input raw material and energy.” Could this ever become a reality, you decide:
http://www.youtube.com/wat
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