"I went from knowing nothing about the field to publishing cryptanalysis at conference almost entirely through what I've learned from downloaded papers - my "dead tree" cryptographic bookshelf is very minimal."
You just described what every graduate student has to do in order to complete their work. If everything you need to do your thesis is in a book then it has already been done ad nauseum.
Another quick note. There are free journals on line that are free to publish in as well as to read. The up keep can carried simply by ad revenue or donated by people in the field or a technical organization.
The only reason it may have waned is the fact that its frickin' hard to make anything useful with nanotechnology right now. Also, the bandwagon has gotten pretty full by now, people were probably sick of waiting in line to jump on.
...and I have to agree with the reviewer. The book doesn't spend much time on the emotional or philosophical issues the people involved in developing the bomb were experiencing.
I believe it was meant strictly as a factual account of how things progressed, who did what, etc. It definitely was interesting to see how physics was brought to the US and the fact the US was way behind in science before the biggest minds in Europe started coming over because of the war.
All in all a good long read, sometimes too much detail in spots but iteresting nonetheless.
It's hard to say what would have happened had brought many of these high volume, low margin products to market. As was stated in an earlier post, Xerox is a compnay that deals with low volume, high margin products. They also make money by selling services. This was how they made their money and it made sense to keep going in that direction. Other very large companies, like GE, do this.
I think their biggest mistake was not liscencing all those great ideas.
using quantum dots does not solve the total efficiency problem. The overall efficiency of a LED is the product of the injection efficiency, the extraction efficiency, and the internal quantum efficiency. The inorganic quantum dots will make the internal quantum efficiency large, this is how well the device converts the injected electrons into light. However, the big stumbling block is the injection effeciency, how well the injected current is converted to electron-hole pairs for generating light. When this efficiency is low, a large amount of the applied power is lost to heat. This will need to be overcome as well before OLEDs of any type make as a commercial technology.
Also the cadmium selenide system is known to have lifetime issues. These, and related, materials were the first candidates for blue/green LEDs and lasers but suffered from horrible lifetimes.
isn't this what happens with sale of any other product? I mean when you own a store and lose a certain percentage of revenue to shoplifting, etc. typically you raise your prices to compensate the additional overhead to your business. In that way, the other consumers pay for stuff they didn't steal.
I don't want to see this happen either, but ther is precedent for it.
It helps to be big. If you don't have the cash for marketing it can be very tough to get your game out there. That is the whole reason game developers connect with publishers in the first place, the money for ads.
How about the number of people that got accepted but aren't worth the paper they received? I've seen plenty of graduates from top schools that might aw well stay home given what they actually contribute. In my opinion, education is what you make of it. If your lucky, the school you go to will point you inthe right direction as to what to learn. The learning part is up to you. Especially in grad school where you are expected to learn everything on your own anyway. School is not the solution, it is just a tool. Nothing is automatic.
DWDM is a technology that has been around for many used. Not only has it been around for a long time, it is heavly used by the telecom industry. It is a great way to increase throughput without more fiber. The disruptive technology in the telecom industry will be a number of technlogies that are either here already or just aonrd the corner. In the case of DWDM, highly integrated modules and widely tunable laser source would bring the cost of high speed transmission way down. In the metro area CWDM (Coarse WDM) is expected to bring WDM to masses so to speak. CWDM does require the same expensive laser sources, as well as passive components, as DWDM. Should be the next big thing for short haul commnications.
I try to add value when I can. I can't contribute too much to the computer related articles beause that is not my area, I come here to learn about that. So when these semiconductor related articles pop up, I try to join in and compare my understanding to others. But alas, things get misinterpreted which is fine. It's part of the system here and I have more to worry about (like finishing my degree). Anyway, thanks for your support!
The extraction efficiency of GaAs is limited by the critical angle, you are correct in this. However, this can be overcome to some degree by microcavity structures ot photonic bandgap structures. Still the material must have a high internal quantum efficiency to produce a large amount of light, single crystal Si alone does not have this. Doped Si may be better but it is still going to be much lower than the near 100% acheivable in GaAs.
This is what I was refering to. Photonic crystals are resonant structures that can enhance the emission or propagation of certain wavelengths in a structure.
Even with this help, single crystal Si will never be able to produce ligth as efficiently as GaAs.
The silicon itself is not generating the noise. It's radiating from the traces of metal that propagate the eletrical signals around the chip, hence the crosstalk and timing issues that can plague electronic circuits.
The latter. Totally Karma whored...although I wasn't the one that moderated the post up...
My statement was also meant as more of an agreement with the article. I didn't need to read the article to know this was true because I work in the industry. I do agree that the moderation is undeserved however.
When you place dopants in a semiconductor, new states are created in the bandgap of the host material. Electrons like to be at the lowest energy possible in semiconductors and therefore can favor these new transistions that arise, especially in indirect bandgap materials. It still will be some what of an indirect transition however and will be relatively inefficient in indirect materials.
However, the fact that Si has an indirect bandgap means it will never be as efficient as its direct gap brethren, such as GaAs.
The addition of a rare earth element such as Erbium increase the light output substantially as you say. However, the emission spectrum is very broad and likely undesired. A rare earth dopant and a resonant cavity structure however would be a good candidate for efficient emission.
Being able to integrate light emitting semiconductor devices together with electronic circuits is one of the holy grails of the semiconductor industry. Not only would the benefit come to increasing the speed of processors, optoelectronic devices would benefit greatly from this technology through integration. The cost savings and increased functionality would be incredible. Can't wait for it to become a reality.
Slashdot Mirror
"I went from knowing nothing about the field to publishing cryptanalysis at conference almost entirely through what I've learned from downloaded papers - my "dead tree" cryptographic bookshelf is very minimal."
You just described what every graduate student has to do in order to complete their work. If everything you need to do your thesis is in a book then it has already been done ad nauseum.
Another quick note. There are free journals on line that are free to publish in as well as to read. The up keep can carried simply by ad revenue or donated by people in the field or a technical organization.
The only reason it may have waned is the fact that its frickin' hard to make anything useful with nanotechnology right now. Also, the bandwagon has gotten pretty full by now, people were probably sick of waiting in line to jump on.
...and I have to agree with the reviewer. The book doesn't spend much time on the emotional or philosophical issues the people involved in developing the bomb were experiencing.
I believe it was meant strictly as a factual account of how things progressed, who did what, etc. It definitely was interesting to see how physics was brought to the US and the fact the US was way behind in science before the biggest minds in Europe started coming over because of the war.
All in all a good long read, sometimes too much detail in spots but iteresting nonetheless.
Using a Scanning Electron Microscope (SEM) or an Atomic Force Micoscope (AFM) would be my guess.
Oops...
Posted to wrong message, sorry.
Using scanning electron microsopy (SEM) would be my guess.
It's hard to say what would have happened had brought many of these high volume, low margin products to market. As was stated in an earlier post, Xerox is a compnay that deals with low volume, high margin products. They also make money by selling services. This was how they made their money and it made sense to keep going in that direction. Other very large companies, like GE, do this.
I think their biggest mistake was not liscencing all those great ideas.
using quantum dots does not solve the total efficiency problem. The overall efficiency of a LED is the product of the injection efficiency, the extraction efficiency, and the internal quantum efficiency. The inorganic quantum dots will make the internal quantum efficiency large, this is how well the device converts the injected electrons into light. However, the big stumbling block is the injection effeciency, how well the injected current is converted to electron-hole pairs for generating light. When this efficiency is low, a large amount of the applied power is lost to heat. This will need to be overcome as well before OLEDs of any type make as a commercial technology.
Also the cadmium selenide system is known to have lifetime issues. These, and related, materials were the first candidates for blue/green LEDs and lasers but suffered from horrible lifetimes.
Just because the prices would not drop does not mean that theft is not a reason for increasing prices.
isn't this what happens with sale of any other product? I mean when you own a store and lose a certain percentage of revenue to shoplifting, etc. typically you raise your prices to compensate the additional overhead to your business. In that way, the other consumers pay for stuff they didn't steal.
I don't want to see this happen either, but ther is precedent for it.
It helps to be big. If you don't have the cash for marketing it can be very tough to get your game out there. That is the whole reason game developers connect with publishers in the first place, the money for ads.
Beware of the Diakatana Syndrome(TM).
It took forever.
It sucked.
No guarantee it will be good just because it takes a long time to make.
How about the number of people that got accepted but aren't worth the paper they received? I've seen plenty of graduates from top schools that might aw well stay home given what they actually contribute. In my opinion, education is what you make of it. If your lucky, the school you go to will point you inthe right direction as to what to learn. The learning part is up to you. Especially in grad school where you are expected to learn everything on your own anyway. School is not the solution, it is just a tool. Nothing is automatic.
DWDM is a technology that has been around for many used. Not only has it been around for a long time, it is heavly used by the telecom industry. It is a great way to increase throughput without more fiber. The disruptive technology in the telecom industry will be a number of technlogies that are either here already or just aonrd the corner. In the case of DWDM, highly integrated modules and widely tunable laser source would bring the cost of high speed transmission way down. In the metro area CWDM (Coarse WDM) is expected to bring WDM to masses so to speak. CWDM does require the same expensive laser sources, as well as passive components, as DWDM. Should be the next big thing for short haul commnications.
Thanks, I agree.
I try to add value when I can. I can't contribute too much to the computer related articles beause that is not my area, I come here to learn about that. So when these semiconductor related articles pop up, I try to join in and compare my understanding to others. But alas, things get misinterpreted which is fine. It's part of the system here and I have more to worry about (like finishing my degree). Anyway, thanks for your support!
I was speaking of single crystal Si.
The extraction efficiency of GaAs is limited by the critical angle, you are correct in this. However, this can be overcome to some degree by microcavity structures ot photonic bandgap structures. Still the material must have a high internal quantum efficiency to produce a large amount of light, single crystal Si alone does not have this. Doped Si may be better but it is still going to be much lower than the near 100% acheivable in GaAs.
This is what I was refering to. Photonic crystals are resonant structures that can enhance the emission or propagation of certain wavelengths in a structure.
Even with this help, single crystal Si will never be able to produce ligth as efficiently as GaAs.
The silicon itself is not generating the noise. It's radiating from the traces of metal that propagate the eletrical signals around the chip, hence the crosstalk and timing issues that can plague electronic circuits.
The latter. Totally Karma whored...although I wasn't the one that moderated the post up...
My statement was also meant as more of an agreement with the article. I didn't need to read the article to know this was true because I work in the industry. I do agree that the moderation is undeserved however.
When you place dopants in a semiconductor, new states are created in the bandgap of the host material. Electrons like to be at the lowest energy possible in semiconductors and therefore can favor these new transistions that arise, especially in indirect bandgap materials. It still will be some what of an indirect transition however and will be relatively inefficient in indirect materials.
Hope that helps.
The light that GaAs emits is in the infrared. So unless you have some heat detection goggles there wouldn't be much to see.
You have a very good point.
However, the fact that Si has an indirect bandgap means it will never be as efficient as its direct gap brethren, such as GaAs.
The addition of a rare earth element such as Erbium increase the light output substantially as you say. However, the emission spectrum is very broad and likely undesired. A rare earth dopant and a resonant cavity structure however would be a good candidate for efficient emission.
Being able to integrate light emitting semiconductor devices together with electronic circuits is one of the holy grails of the semiconductor industry. Not only would the benefit come to increasing the speed of processors, optoelectronic devices would benefit greatly from this technology through integration. The cost savings and increased functionality would be incredible. Can't wait for it to become a reality.
Sten is that you?
It's the same basic material system.