Nuit Blanche-Transmission of quantum entanglement through a random medium / Terahertz compressive imaging with metamaterial spatial light modulators

http://nuit-blanche.blogspot.com/2014/07/transmission-of-quantum-entanglement.html

There are really two ways to produce some randomness. One is to use a random medium and expect that the laws of transport will provide some sort of multiplexing and the other is to engineer the random multiplexing. This week, we will have another example of the former but today we have an instance of both:

One item that comes with papers that are behind walls: I need to have access to the second paper because I wonder about the "no moving parts" claim. You reader know my email, wink wink. Without further ado:

Transmission of quantum entanglement through a random medium by M. Candé, A. Goetschy, S.E. Skipetrov

We study the high-dimensional entanglement of a photon pair transmitted through a random medium. We show that multiple scattering in combination with the subsequent selection of only a fraction of outgoing modes reduces entanglement of an initially maximally entangled two-photon state. Entanglement corresponding to a random pure state is obtained when the number of modes accessible in transmission is much less than the number of modes in the incident light. An amount of entanglement approaching that of the incident light can be recovered by accessing a larger number of transmitted modes. In contrast, a pair of nonentangled photons does not gain any entanglement when transmitted through a random medium.

Terahertz compressive imaging with metamaterial spatial light modulators by Claire M. Watts, David Shrekenhamer, John Montoya, Guy Lipworth, John Hunt, Timothy Sleasman, Sanjay Krishna, David R. Smith, Willie J. Padilla

Imaging at long wavelengths, for example at terahertz and millimetre-wave frequencies1, is a highly sought-after goal of researchers2, 3 because of the great potential for applications ranging from security screening4 and skin cancer detection5 to all-weather navigation6 and biodetection7. Here, we design, fabricate and demonstrate active metamaterials that function as real-time tunable, spectrally sensitive spatial masks for terahertz imaging with only a single-pixel detector. A modulation technique permits imaging with negative mask values, which is typically difficult to achieve with intensity-based components. We demonstrate compressive techniques allowing the acquisition of high-frame-rate, high-fidelity images. Our system is all solid-state with no moving parts, yields improved signal-to-noise ratios over standard raster-scanning techniques8, and uses a source orders of magnitude lower in power than conventional set-ups9. The demonstrated imaging system establishes a new path for terahertz imaging that is distinct from existing focal-plane-array-based cameras.

OT Abstract-Single exposure compressed imaging system with Hartmann-Shack wavefront sensor

My Note: I found this abstract on Igor Carron's amazing blog Nuit Blanche, and wanted to share it with readers here. Some in the THz community will find this to be of particular interest. Igor's blog is found here:
http://nuit-blanche.blogspot.com

Xiao Xiao ; Yang Zhang ; Xiaowei Liu

http://opticalengineering.spiedigitallibrary.org/article.aspx?articleid=1869898

Xiao Xiao

Xidian University, Department School of Telecommunication Engineering, Xi’an 710071, China

Yang Zhang

Xidian University, Department School of Telecommunication Engineering, Xi’an 710071, China

Xiaowei Liu

Xidian University, Department School of Telecommunication Engineering, Xi’an 710071, China

Opt. Eng. 53(5), 053101 (May 05, 2014). doi:10.1117/1.OE.53.5.053101

History: Received November 27, 2013; Revised March 27, 2014; Accepted April 1, 2014

Text Size: A A A

Abstract.  A new compressed imaging system based on compressed sensing (CS) theory is proposed. One single exposure with a frame sensor can replace a sequence of measurements, which is necessary in the conventional CS imaging systems. First, the phase of the incident light is randomly modulated in the Fourier transform domain using a spatial light modulator. When the modulated light passes through the inverse Fourier transform lens, the information of the optical field will spread out across the entire modulated image. Then, a Hartmann-Shack wavefront sensor is employed to sense the intensity and phase information in the final imaging plane. The resolution of the Hartmann-Shack wavefront sensor is far less than the inherent resolution of the imaging system. Finally, a high-resolution image can be reconstructed from the image partially sampled from the Hartmann-Shack wavefront sensor at any position. The numerical experiments demonstrate the effectiveness of the proposed imaging method.

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Figures in this Article

© 2014 Society of Photo-Optical Instrumentation Engineers

Topics

Compressed sensing ; Compressive imaging ; Imaging systems ; Phase modulation ; Sensors ; Wavefront sensors ; Matrices ; Lenses

Citation

Xiao Xiao ; Yang Zhang and Xiaowei Liu
"Single exposure compressed imaging system with Hartmann-Shack wavefront sensor", Opt. Eng. 53(5), 053101 (May 05, 2014). ;http://dx.doi.org/10.1117/1.OE.53.5.053101

InView Expands Compressive Sensing Workstations Series with Two New Products

My Note: Just saw this on Nuit Blanche, so thanks go to Igor Carron, for posting this.

http://nuit-blanche.blogspot.com/2013/02/inview-announces-compressive-sensing.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+blogspot%2FwCeDd+%28Nuit+Blanche%29

InView Expands Compressive Sensing Workstations Series with Two New Products

Austin, TX, January 31, 2013: InView Technology Corporation, the world leader in Compressive Sensing (CS) imaging products, has expanded its family of CS Workstations with the release of two new systems, the InView222 Compressive Sensing Workstation and the InView223 Spatial Light Modulator. Both systems allow researchers to prototype and test innovative computational imaging algorithms.

The InView222 builds upon the successful InView220 Compressive Sensing Workstation that was introduced by InView in 2012. The InView222 enables researchers to demonstrate novel CS algorithms on a complete hardware imaging platform. It allows researchers to apply measurement bases using a high-speed, spatial light modulator (SLM) sub-system, and to process the modulated image in a measurement sub-system. The measurement sub-system includes a single-diode CMOS detector, followed by an amplifier and analog-to-digital converter.

The InView223 provides a SLM sub-system and is coupled to user’s own measurement sub-system, allowing bench-top experiments in fields of research including computational imaging, computational photography, compressive sensing, and other fields requiring high-speed custom optical modulation.

Both the InView222 and InView223 give researchers an unprecedented ability to apply novel 1024x768 pixel modulation patterns at rates of up to 32,000 patterns per second using a digital micro-mirror device. Both systems accept externally-generated SLM patterns streamed from an external source over an eight lane, PCI Express 2.0 bus, which has sufficient speed to allow the SLM to run at full speed. The user does not need to buffer patterns in development system memory as is required by other micromirror-based products.

Both products leverage an objective lens optimized for visual light and use a standard M42 lens mount.

“InView’s Compressive Sensing Workstation Family allows researchers to easily demonstrate their advanced imaging algorithms on easy-to-use hardware,” stated Dr. Bob Bridge, InView’s founder and CEO. “These new products are a welcome addition to the Workstation launched last year.”

About InView

InView specializes in the design, development and manufacturing of imaging products based upon Compressive Sensing technology, including low-cost shortwave infrared (SWIR) cameras. Leveraging its patents in Compressive Sensing, InView’s InGaAs-based SWIR solutions can achieve superior results at dramatically reduced prices, and provide leadership price-performance for microscopy, security, surveillance, maritime navigation, military and other applications.

Igor Carron, on NUIT BLANCHE writes about this blog, terahertz and CMOS

My Note: Anytime Dr. Igor Carron, mentions a topic, people listen and take notice, so I was very pleased he commented today on his cutting-edge, highly regarded blog, Nuit Blanche, about the recent stories found here (which I repost below). Thank you Dr. Carron for mentioning Terahertz Technology.

http://nuit-blanche.blogspot.com/

Of Paradigm Shifts and Regime Changes

One of the reasons some technologies do not become fully mature or simply die off comes from a competition effect. If you are developing a technology based on the fact that some sensors are expensive, such is the case in some regimes for compressive sensing, then you are in a competition with not just similar technologies (different sampling techniques) but also with technologies that aim for a much cheaper sensor. Case in point, Randy pointed out to us this past week, the emergence of two or three CMOS based solutions for Terahertz imaging:

• Revisiting TeraTop-TeraTOP Aims to Revolutionize THz Imaging
• Exclusive Comments from Dr. Ken O at the University of Texas, Dallas,regarding CMOS and Terahertz
• New Research Could Mean Cellphones That Can See Through Walls
• A Cheap Terahertz Camera

for some background

• Conscripting Terahertz Sensors

Liked this entry ? subscribe to Nuit Blanche's feed, there's more where that came from. You can also subscribe to Nuit Blanche by Email, explore the Big Picture in Compressive Sensing or the 

End of the Year Blog post, with comments by Dr. Daniel Mittleman, Thomas Tongue,Rob Risser among others, along with my pick for top 5 stories of the year

The end of another year on the Terahertz Technology blog has arrived, and it’s time for my end of the year post. Thank you for reading the blog. Viewer interest has made keeping the blog updated, and current, fun  rather than a chore. Frankly, the greatest benefit for me about creating the blog, is that I’ve learned  about an incredible number of truly amazing scientific developments, companies, and projects which I had never heard of. I’ve also had the pleasure of making contact with a large number of individuals all over the world, who are at the cutting edge of THz development. In terms of viewing audience, the blog had over 8,000 discrete web-visits  in July, and almost that many again this month. The really amazing statistic for me is that the blog has been viewed in 112 Countries. Pretty amazing,  considering, I have no real technical background in Terahertz. So once, again, thank you for reading.

I really have appreciated hearing from some of the leading names in the THz field, some of those comments follow, (some comments were in response to my request for statements about the current state of THz, some were for information on how to have better access to the blog, via RSS, twitter or other mediums, and some were to share information with me. I include just a few of those comments.

“Hi Randy,
As far as I am concerned, the field is still very strong and robust, with an increasing number of research groups and applications spin-offs. One expects research fields to saturate eventually, but with the THz world this has not yet happened. And anyway, we're still having lots of fun, so it's all good. I've been to several THz conferences this year, and they were all very well attended and buzzing with good ideas.” (remainder omitted).

Regards,

Dan (Mittleman)
Rice University

“Hi Randy,

 Things are going well here, we have just moved into a larger facility so I apologize for the delay in writing back. The big news in the past few weeks has been the Prism Awards. Our micro-Z handheld THz system is one of three finalists in the Defense and Security category, and we should find out at the awards banquet at Photonics West which product has won.
All the best,
 -Thomas Tongue
 -------------------------------------------------------
 Thomas Tongue
 CEO, Zomega Terahertz Corporation

Dear Randy,

My name is Wei Jan and I am currently project manager at Chalmers Innovation. Chalmers Innovation is a high-tech business incubator which assists in commercialization of research from Chalmers University in Göteborg, Sweden. Our company’s webpage is: http://www.chalmersinnovation.com/
I am currently undertaking a project on terahertz (THz) radiation sensors. A group of researchers from Chalmers University have developed a novel sensor for THz detection. The sensor is essentially a micro-bolometer, and the novel properties of the sensor are:

1. Broadband sensitivity (possibly up to 10THz at room temperature)
2. High sensitivity (1uW for operation at room temperature)
3. Miniaturized (~1mm in diameter)
4. Ability to be arranged in a camera-like array for real-time imaging (response time about 40ms)
The technology is different from pulse and continuous THz systems because we do not require a specific THz source. However, we are also not a passive system as the sensor is sensitive enough to pick up ambient THz radiation which bounces off the object of interest. Another difference is that we only collect information on amplitude, without phase information, because the sensor functions as a bolometer. The technology is currently in the proof-of-concept phase….. (remainder of letter omitted..)….
Thank you.
Med vänliga hälsningar/Kind regards
Wei Jan Wang
 Evaluation Officer
Chalmers Innovation
 Stena Center 1D

412 92 Göteborg, Sweden

Tel: +46 - 31 772 81 00

(Wei Jan Wang, has promised to send me some articles regarding his findings to post here. I look forward to it.)


"Hi Randy,

I wanted to say thank you for your educational role in helping the public better understand THz, the subtle and often esoteric differences in generating and detecting THz waves, and the real "commercial" significance of these differences.  THz is moving out of the laboratory and into the industrial and homeland security applications.  The true test for industry is the ROI, or payoff, for process control and quality control on the manufacturing floor.  The THz sensor is an enabler for improved productivity and quality, but often only a fraction of the CAPEX our customers invest in their new or retooled manufacturing lines.  We ( API) are making great progress on adoption of THz on the factory floor, as we have been reporting during the past few years.  In addition, our cost reductions and total "value added" content strategy have enabled API to develop solutions that are the lowest cost with the highest performance; both of which are required by the industrial and homeland security markets.


Picometrix ( API) has been working on the technology performance, ruggedization and  applications since 1997, almost 14 years.  Technology adoption usually takes longer than all wished, but as it hits the inflection point, adoption accelerates.  We are really just now seeing the first industrial deployment, which is very exciting for our team that has been dedicated and focussed on this for all those years.  Remember, the Beta nuclear guage was first introduced in 1948 by LFE corporation (now owned by Thermo Fisher).  It took the beta guage a while to penetrate the market.  We at API believe we are on that same penetration path for THz and are excited about the challenges and opportunities, as I hope we have conveyed on our quarterly conferences calls and periodic press releases.  


We hope you and yours have a happy, healthy and prosperous new year.
Warm Regards,
Rob Risser
COO API"

“Randy,
 Your Terahertz Technology Blog is a very nice collection of stories. Thanks for mentioning us at times”
(remainder of email omitted)
Gerhard

 Gerhard S. Schoenthal, PhD • Director of Microelectronics
 Virginia Diodes, Inc. • www.vadiodes.com
 979 2nd St. SE, Suite 309 • Charlottesville, VA 22902

The blog has also been mentioned several times on one of the really innovative, and exciting technical blogs found on the net, Nuit Blanche, such as on March 8^th, 2011,

Randy: Extremely High Refractive Index Terahertz Metamaterial, Enhancing Terahertz scanners using Compressive Sensing Technology. Randy is a lawyer but he blogs on Terahertz technology, who would have thought. The interesting element of Teraherz imaging is that not much is known with regards to the interaction of light with matter. In other words, the dictionary is not well known in the first place.

Dr. Igor Carron, publishes/authors, Nuit Blanche, and I wanted to remind him here of his comment, on August 12^th, 2011. “I am due with a blog entry on Randy's blog on terahertz imaging and compressive sensing. So, Randy if you read this, I have not forgotten you :-).” 

Thanks Igor, my readers would love to hear from a man of your genius, and I look forward to including your post in 2012.
http://nuit-blanche.blogspot.com/2011/12/inception-and-philosophy.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+blogspot%2FwCeDd+%28Nuit+Blanche%29

So now, let’s discuss some of the trends, developments, top stories that were posted on the blog in 2011. All comments, are my layman’s thoughts, and perspective on how the year unfolded in Terahertz, based upon the blog entries posted here. I welcome your comments and analysis of the field.

2011 was a year of tremendous discovery, and advancement in this still virgin technology.

The “bridge” over the THz gap, between electronics, and photonics, is quickly being closed, as chronicled in the entries posted here in 2011. In the research and development arena, the excitement about THz, is palpable, and I believe Dr. Dan Mittleman’s comments above, reflect the overall sense that big things are looming in the THz arena.

In contrast, the move of THz from the research laboratory onto the factory floor, and into commercial viability, has been slow, disappointing,  and almost painful. (At least, it’s been painful, to those of us who have invested in the commercial promise of THz. In my opinion, commercial acceptance is really a reflection not only of slow-market acceptance, but also World-wide financial conditions in general).

Let’s discuss the exciting developments in the area of research and funding first, and then turn to the topic of commercial development..

Terahertz funding continues to grow

One of the really interesting things I learned about and observed is the remarkable amount of money which is flowing into THz development in terms of grant money and agency funding. This fact, can’t be discounted given the world-wide financial malaise which has infected the World financial markets since 2008. These days, precious research dollars are only spent in areas where there is a reasonable chance of significant social and/or scientific gain, and the number as well as the size of grants made to a number of University laboratories, and to private companies, is significant, and demonstrates that after careful thoughtful evaluation, THz was right at the top of the funding list.

Grants of 6.3 million dollars to Norte Dame University, 3 million to Ohio State, and 21 million to the University of Utah, are but a few of the many grants to develop THz that were mentioned on the blog.

In the private sector, and in the United States, Advanced Photonix and it’s subsidiary, Picometrix received a number of new US government funded develop contracts, but Virginia Diodes,  Bridge12 and others have enjoyed the fruit of government funded development projects. Space doesn’t permit me to mention them all

There are exciting privately funded projects, also underway, such as the Agilent Technologies, establishment of a millimeter wave research center at the University of California Davis. TeraView is collaborating with the Hyperspectral Engine Lab for Integrated Optical Systems, at Ohio State University to develop semiconductor package failure analysis. These are just a few of the collaborations, and joint ventures mentioned over the last year.

In Europe, the Dot12, and TeraTOP, are but two of the larger well-funded consortiums combining both government, and private company resources to develop products which will be commercial viable, across a vast and diverse spectrum of fields.

Look for some major breakthroughs in 2012.

The trend is towards smaller, more powerful and less costly devices

I have to admit that before I started collecting articles for this blog, I had never heard of metamaterials or graphene. If you follow the blog, you will have notice that there have been an explosion of stories and articles tracking the exciting progress being made with the development of materials, at the atomic level, which are much more conducive to the propagation of THz radiation which is more controlled and more powerful. These developments are the future of THz  commercialization and usefulness. In the present tense, there are any number of companies which have worked on building smaller more powerful units. Advanced Photonix, is set to unveil a next generation T-Ray4000, which promises to be even smaller, more powerful, and less costly than the current generation.

Handheld units, such as the Zomega, Mini-Z handheld, mentioned by Thomas Tongue, will help move Terahertz from the laboratory to the factory floor. The blog has scores of other examples, and if you would like your company mentioned, please comment on this post or send me an email, and I will mention your work.

So now let me pick my top 5 blog stories of 2011 based upon what I thought was most likely to substantially impact THz development over the next year..

1. The work by Edmund Linfield, (among others) in developing a “pulsed” quantum cascade laser, which is 10,000 times more powerful than any similar device and can emit in separate pulses rather than a continuous stream appears to be a huge advance for THz development, and garners my top story of the year.

   http://terahertztechnology.blogspot.com/2011/04/terahertz-pulsed-scanning-which-is.html

2.Applied Research and Photonics, Inc. as the winner of this year’s CLEO/Laser Focus World Innovation Award is my number two pick The award recognizes the company “for the development of a highly sensitive, low-power terahertz scanning reflectometer capable of directly measuring both the concentration gradient and kinetics of permeation of an ingredient across the thickness of a substrate in real time and in a non-invasivefashion.  http://terahertztechnology.blogspot.com/2011/04/applied-research-and-photonics-inc.html

3.   Agilent Technologies decision to partner with Bridge12, to develop a series of new ultra-high-field nuclear magnetic resonance (NMR) spectrometers at 850 MHz and 1GHz is my third choice because it signifies that Bridge12 will have now have the funding to carry their innovative, and highly useful products into the commercial arena.

http://terahertztechnology.blogspot.com/2011/04/agilent-technologies-to-develop-1-ghz.html

 4 Rensselaer Polytechnic Institute (RPI)  creative  encoding of  THz information into acoustic waves, is my fourth pick.

   http://terahertztechnology.blogspot.com/2011/07/listening-to-terahertz-electromagnetic.html

    

5.  My last pick for top blog post, is one that envisioned would be my top pick for the year, when it first came out. It’s no secret I am an investor in Advanced Photonix, and toward the end of 2010, I was frankly giddy, with excitement, over it’s prospects to make a significant move into the commercial arena,  in a variety of quality control areas.  When news of the first commercial sale of THz to a private company making roofing materials was announced last January, I anticipated it was the first of many such announcements  that would be made  in 2011.  Unfortunately, I was wrong, and the actual integration of the T-Ray 4000, onto the factory floor took over 9 months.  In hindsight, my estimates regarding commercial acceptance ot THz, was naïve. Making laboratory equipment commercially hardened,  developing all of the software and hardware applications for use by a company seeking to save time and money, day after day, is  a complex and difficult process. Fabricating laboratory devices into a usable product to be used on a  factory line, is also clearly a  challenging endeavor . The fact that API has been working daily to overcome these obstacles since 2005, when it sold a T-Ray system to NASA  to be used in scanning the space shuttle tiles and foam for defects, has given them several years of hands-on experience. I’m optimistic that 2012 will be the year for API, that I had hoped 2011 would be.  Time will tell. http://terahertztechnology.blogspot.com/2011/01/advanced-photonix-inc-announces-first.html

So, thank you all again for reading  the blog. I have enjoyed learning about so many exciting things going on in the development of  Terahertz, and look forward to bringing you more current stories over the next year.  

Happy New Year to you all!!

Randy Knudson 
knudson.randy@gmail.com

         

One more Semi-OT post; More on Compressive sensing's use in scanning technology from Nuit Blanche

MY NOTE: Wish I could say that I truly understood the mathematics behind compressive sensing, but I do understand the concept, as ably presented by Igor Carron on his blog Nuit Blanche, and I can also see how it will influence and make all scanning technologies better. (Igor has promised me a blog post here, and I look forward to it, when he has the time)

http://nuit-blanche.blogspot.com/2011/12/new-sensor-around-blogs-in-80-hours-and.html

Here is a new compressive sensor: Compressive Fluorescence Microscopy for Biological and Hyperspectral Imaging by Vincent Studer, Jérome Bobin, Makhlad Chahid, Hamed Moussavi, Emmanuel Candes and Maxime Dahan. The abstract reads:

The mathematical theory of compressed sensing (CS) asserts that one can acquire signals from measurements whose rate is much lower than the total bandwidth. Whereas the CS theory is now well developed, challenges concerning hardware implementations of CS-based acquisition devices—especially in optics—have only started being addressed. This paper presents an implementation of compressive sensing in fluorescence microscopy and its applications to biomedical imaging. Our CS microscope combines a dynamic structured wide-field illumination and a fast and sensitive single-point fluorescence detection to enable reconstructions of images of fluorescent beads, cells and tissues with undersampling ratios (between the number of pixels and number of measurements) up to 32. We further demonstrate a hyperspectral mode and record images with 128 spectral channels and undersampling ratios up to 64, illustrating the potential benefits of CS acquisition for higher dimensional signals which typically exhibits extreme redundancy. Altogether, our results emphasize the interest of CS schemes for acquisition at a significantly reduced rate and point out to some remaining challenges for CS fluorescence microscopy

More on Compressive Sensing for enhancing imaging technology including THz

MY NOTE: IGOR CARRON, CONTINUES TO BLOG ABOUT ONE OF THE MOST INTERESTING ADVANCES IN CONTEMPORARY THOUGHT, WHICH IS COMPRESSIVE SENSING. I DON'T HAVE EITHER THE MATHEMATICAL, OR TECHNICAL BACKGROUND,  TO UNDERSTAND MORE THAN, "BROAD OUTLINES", OF THE IDEAS BEHIND MANY DEVELOPMENTS GOING ON IN THIS AREA. IT'S OBVIOUS TO ME, THAT COMPRESSIVE SENSING WILL CHANGE HOW IMAGING TECHNOLOGIES WILL BE UNDERSTOOD AND  DEVELOPED IN THE FUTURE.
THE FOLLOWING,  IS ONE SMALL PIECE, FROM IGOR'S BLOG, NUIT BLANCHE,  WHICH IS HIS REPOST, OF AN ABSTRACT, ( WHICH WILL BE OF INTEREST TO MANY READERS INTERESTED IN MEDICAL IMAGING, WITH THz OR OTHER SCANNING TECHNOLOGY.)
http://nuit-blanche.blogspot.com/2011/09/its-stunning-and-quite-amazingly-rich.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+blogspot%2FwCeDd+%28Nuit+Blanche%29





Generative-Discriminative Basis Learning for Medical Imaging by Nematollah K. Batmanghelich, Ben Taskar, Christos Davatzikos. The abstract reads:

This paper presents a novel dimensionality reduction method for classification in medical imaging. The goal is to transform very high-dimensional input (typically, millions of voxels) to a low-dimensional representation (small number of constructed features) that preserves discriminative signal and is clinically interpretable. We formulate the task as a constrained optimization problem that combines generative and discriminative objectives and show how to extend it to the semisupervised learning (SSL) setting. We propose a novel largescale algorithm to solve the resulting optimization problem. In the fully supervised case, we demonstrate accuracy rates that are better than or comparable to state-of-the-art algorithms on several datasets while producing a representation of the group difference that is consistent with prior clinical reports. Effectiveness of the proposed algorithm for SSL is evaluated with both benchmark and medical imaging datasets. In the benchmark datasets, the results are better than or comparable to the state-of-the-art methods for SSL. For evaluation of the SSL setting in medical datasets, we use images of subjects with Mild Cognitive Impairment (MCI), which is believed to be a precursor to Alzheimer’s disease (AD), as unlabeled data. AD subjects and Normal Control (NC) subjects are used as labeled data, and we try to predict conversion from MCI to AD on follow-up. The semi-supervised extension of this method not only improves the generalization accuracy for the labeled data (AD/NC) slightly but is also able to predict subjects which are likely to converge to AD

Fast terahertz reflection tomography using block-based compressed sensing

Image via Wikipedia

MY NOTE: I CAME ACROSS THIS ABSTRACT TONIGHT ON ONE OF THE WEB'S MOST INTERESTING BLOGS,  NUIT BLANCHE, BY DR. IGOR CARRON. I DON'T KNOW HOW MANY THz  COMPANIES ARE EXPLORING THE USE OF COMPRESSIVE SENSING TO ENHANCE TERAHERTZ IMAGING, BUT THE SMART & CREATIVE ONES WILL BE EMPLOYING IT, IN THE NEAR FUTURE IS MY BET.





http://nuit-blanche.blogspot.com/
by Sang-Heum Cho, Sang-Hun Lee, Chan Nam-Gung, Seoung-Jun Oh, Joo-Hiuk Son, Hochong Park, and Chang-Beom Ahn. The abstract reads:
In this paper, a new fast terahertz reflection tomography is proposed using block-based compressed sensing. Since measuring the time-domain signal on two-dimensional grid requires excessive time, reducing measurement time is highly demanding in terahertz tomography. The proposed technique directly reduces the number of sampling points in the spatial domain without modulation or transformation of the signal. Compressed sensing in spatial domain suggests a block-based reconstruction, which substantially reduces computational time without degrading the image quality. An overlap-average method is proposed to remove the block artifact in the block-based compressed sensing. Fast terahertz reflection tomography using the block-based compressed sensing is demonstrated with an integrated circuit and parched anchovy as examples.
__
BRIEFLY, IGOR HAS WRITTEN THE FOLLOWING INTRODUCTORY THOUGHT ABOUT COMPRESSIVE SENSING:

Compressed Sensing or Compressive Sensing is about acquiring a sparse signal in the most efficient way possible (subsampling) with the help of an incoherent projecting basis. Unlike traditional sampling methods, Compressed Sensing provides a new framework for sampling signals in a mutiplexed manner. The main theoretical findings in this recent field have mostly centered on how many multiplexed signals were necessary to  reconstruct the original signal and the attendant nonlinear reconstruction techniques needed to demultiplex these signals.  Another equally important thrust in the field has been the making of sensing hardware that could produce directly the multiplexed signals. (Read more here:

http://sites.google.com/site/igorcarron2/cs)
I ALSO FOUND THIS SITE VERY HELPFUL:
http://sunbeam.ece.wisc.edu/csaudio/

(HERE IS A SMALL BLURB):
Recently Professor Jordan Ellenberg wrote an article in Wired Magazine, 'Fill in the Blanks', describing how Compressed Sensing is being applied to signals such as MRI. In order to illustrate the concept, the article had a demonstration of how Compressed Sensing (CS) reconstruction works on an image of President Barack Obama.

Enhancing Terahertz scanners using Compressive Sensing Technology

MY NOTE: THIS STORY CAUGHT MY EYE BECAUSE IT MENTIONS A NEW AGREEMENT SIGNED BY IQT, SOME OF YOU WILL REMEMBER ENTERED INTO AN AGREEMENT WITH ADVANCED PHOTONIX ON NOVEMBER 5TH, 2010, TO ENGINEER A LOW COST ANOMALY DEVICE USING THz, 

http://terahertztechnology.blogspot.com/2010/11/advanced-photonix-to-engineer-low-cost.html

INVIEW TECHNOLOGY DOES NOT ACCESS THE SPECTRAL WAVELENGTH IN THE MANNER WE TYPICALLY DISCUSS HERE, BUT RATHER USES COMPRESSIVE SENSING TECHNOLOGY. ONE HAS TO WONDER IF IQT INTENDED TO SOMEHOW ENHANCE THE ANOMALY DETECTION DEVICE WITH COMPRESSIVE SENSING TECHNOLOGY. YOUR THOUGHTS AND COMMENTS APPRECIATED. 
LINK ON COMPRESSIVE SENSING:
http://www.wired.com/magazine/2010/02/ff_algorithm/
_____________________

InView Technology Corporation, a world-leading developer of innovative computational imaging products, today announced a strategic investment and development agreement from In-Q-Tel (IQT), the strategic investment firm that identifies innovative technology solutions to support the missions of the U.S. Intelligence Community.

InView's business is built on proprietary Compressive Sensing technology that allows high-performance cameras and hyperspectral imagers to be built using greatly simplified detector architectures. Compressive Sensing technology substitutes innovative math for complex electronic components, allowing cameras and hyperspectral imagers to be built at lower cost and with higher resolution. The technology is especially compelling for those wavelengths where it is difficult to build cost-effective, high-resolution focal plane arrays.

"InView has demonstrated innovative camera technologies," said Syd Ulvick, Vice President, Physical and Biological Technologies practice at IQT. "The unique computational imaging architecture provides tremendous opportunities to develop cutting-edge products."

"We are delighted to have IQT as a strategic investor and partner," said Bob Bridge, Founder and CEO of InView. "InView has an innovative technology platform that works across wavelengths including ultra violet, visual, infrared, and terahertz. We are pleased that working with IQT will open the door to opportunities to tailor our technology to meet the needs of the U.S. Intelligence Community."

About InView Technology Corporation:

InView Technology Corporation is a privately-held company headquartered in Austin, Texas. InView delivers high-performance cameras and hyper-spectral imagers using proprietary computational imaging technology that result in unmatched price-performance across the electromagnetic spectrum. You may find more information at www.InViewCorp.com.

About IQT:

In-Q-Tel is the strategic, not-for-profit investment firm that works to identify, adapt, and deliver innovative technology solutions to support the missions of the U.S. Intelligence Community. Launched in 1999 as a private, independent organization, IQT’s mission is to identify and partner with companies developing cutting-edge technologies that serve the national security interests of the United States. To learn more about IQT, visit www.iqt.org.  Read more

Read more: http://www.sunherald.com/2011/02/22/2882366/inview-technology-corporation.html#ixzz1EnKnzOKr


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