PhD Dissertation Defense Announcement
Electrical Engineering

Polarization-insensitive all-optical dual pump-phase trans-multiplexing from 2 × 10-GBd OOKs to 10-GBd RZ-QPSK using cross-phase modulation in a passive nonlinear birefringent photonic crystal fiber

Tanvir Mahmood

2:00pm Thursday, 24 September 2015, ITE325b

Considering the network size, bit rate, spectral and channel capacity limitations, different modulation formats may be selectively used in future optical networks. Although the traditional metropolitan area networks (MANs) still use the non-return-to-zero on-off keying (NRZ-OOK) modulation format due to its technical simplicity and therefore low cost, QPSK format is more advantageous in spectrally efficient long-haul fiber optic transmission systems because of its constant power envelope, and robustness to various transmission impairments. Consequently, an important problem may arise, in particular how to route the OOK-data streams from MANs to long-haul backbone networks when the state of polarization (SOP) of the remotely generated OOK is unpredictable. Hence, the focus of this dissertation was to investigate a polarization-insensitive (PI) all-optical nonlinear optical signal processing (NOSP) method that can be implemented at the network cross-connect (X-connect) to transfer data from a remotely and a locally generated OOK data simultaneously to more effectual QPSK format for long-haul transmission. By utilizing cross-phase modulation (XPM) and inherent birefringence of the device, the work demonstrated, for the first time, PI all-optical data transfer utilizing dual pump-phase transmultiplexing (DPTM) from 2 × 10-GBd OOKs to 10-GBd RZ-QPSK in a passive nonlinear birefringent photonic crystal fiber (PCF). Polarization insensitivity was achieved by scrambling the SOP of the remotely generated OOK pump and launching the locally generated OOK pump and the probe off-axis. To mitigate polarization induced power fluctuations and detrimental effects due to nearby partially degenerate and non-degenerate four wave mixings, an optimum pump-probe detuning was also utilized. The PI DPTM RZ-QPSK demonstrated a pre-amplified receiver sensitivity penalty < 5.5 dB at 10−9 bit-error-rate (BER), relative to the FPGA-precoded RZ-DQPSK baseline in ASE-limited transmission system. The effect of the remotely generated OOK pump OSNR degradation on the PI DPTM RZ-QPSK was also investigated and it was established that 10−9 BER metric was attainable till the remotely generated OOK pump reached the threshold OSNR limit of 34 dB/0.1nm. Finally, DWDM transmission performance of the PI DPTM RZ-QPSK signal was evaluated using a 138-km long recirculating loop and it was demonstrated that the PI DPTM RZ-QPSK can be transmitted over 1,500 km before it reached ITU-T G.709 7% HD-FEC overhead limit. This propagation distance was well beyond the transmission requisites of any typical metro network (≈ 600 km). Furthermore, it was demonstrated that, within the threshold limit, OSNR degradation of the remotely generated OOK pump had minimal impact on the transmission distance of the PI DPTM RZ-QPSK before it reached 7% HD-FEC overhead limit.

Committee: Drs. Gary M. Carter (Chair), Anthony M. Johnson, Fow-Sen Choa, Tinoosh Mohsenin, Thomas E. Murphy (ECE,UMCP), William Astar

Ph.D. Dissertation Proposal

Verifiable Randomness and its Applications

Christopher Vatcher

10:30am Thursday, 24 September 2015, ITE 325b

We propose to create a public verifiable randomness beacon, to integrate with the Random-Sample Voting system, constructed to be secure against adversaries who have even almost complete control over the system’s source of public randomness including the entropy source.

By verifiable randomness, we do not mean we can prove a sequence of bits to be random. Instead, verifiability means it is possible to prove: (a) a consumer used uniform bits originating from a specific entropy source and therefore cannot lie about the bits used; and (b) the bits used were unpredictable prior to their generation and, with overwhelming probability, were free of adversarial influence. This is in contrast to ordinary public randomness where parties must agree to trust some randomness provider, who becomes a target of corruption. Verifiable randomness is an enhancement of public randomness used to perform random selection in voting, conduct random audits, preserve privacy, generate random challenges for secure multi-party computation, and public lottery draws. Random-Sample Voting specifically requires verifiable randomness for random voter selection and random audits.

Our work extends the work of Eastlake and Clark and Hengartner by considering (a) adversaries who have fine control over the entropy source and (b) physical entropy sources, which we can make verifiable.

Our specific aims include (a) creating adversary models for three entropy source abstractions based on trusted providers, sensor networks, and distributed proof-of-work systems; (b) create a verifiable random beacon that integrates each model; (c) integrate our work with the Random-Sample Voting system; and (d) integrate with NIST’s beacon and propose a verifiable randomness standard based on our work.

Our method is to weaken the trust assumption on the entropy source by introducing verifiable entropy sources, which have mechanisms for limiting adversarial influence and accumulating evidence that their outputs obey a known distribution. Combined with an appropriate randomness extractor, we can generate verifiable random bits. Using sources like weather, we will construct a verifiable randomness beacon: a public randomness provider unencumbered by generous and often unfounded trust assumptions. Such a beacon can serve as a singular gateway for accessing and aggregating multiple entropy sources without compromising the randomness provided to consumers.

Committee: Drs. Alan T. Sherman (Chair), Konstantinos Kalpakis, Weining Kang (Math/Stat), David Chaum (Random-Sample Voting), Aggelos Kiayias (University of Athens)

National Hispanic Heritage Month: 

Do you want to learn more about U.S. American and global holidays?

Are you interested in learning more about different customs, events, and heritage months? 

Do you like to try ethnic-specific recipes?

If your answer is ‘yes’ to any of the above questions, here is a great resource for you!

Check out our online Diversity Resource Calendar  accessible through your myUMBC login that provides detailed information on U.S. American and global holidays, customs, events, heritage months and ethnic-specific recipes.

The calendar is also available on Student Life's website:

http://osl.umbc.edu/diversity/mosaic

We’re proud to announce the Critical Social Justice: Baltimore 365 keynote “Baltimore in Action: Always Rising,” which will feature prominent social justice advocates from across the city. Rather than having a single keynote speaker as we did in past years with Franchesca Ramsey and Jay Smooth, we look forward to hosting a dynamic conversation among several of the leading voices working to create change in our community.

Our featured keynote panelists include:

• Rev. Dr. Heber Brown, III, faith-based activist and community organizer
• Dr. Marisela B. Gomez, public health advocate and author
• Tawanda Jones, activist and sister of Tyrone West
• Jacqueline Robarge, founder of Power Inside
• Kwame Rose, social activist and hip-hop artist
• Moderated by radio host Marc Steiner 

The keynote event will be held on Tuesday, October 20th in the University Center Ballroom. Doors open at 6:30pm and the keynote will begin at 7pm, immediately followed by a meet-and-greet reception with the panelists.

This event is free and open to the public. If you have questions or need accommodations, please contact the Women’s Center at womens.center@umbc.edu. 

Want to learn more about our panelists? Stay tuned this week as we profile each speaker and highlight what you need to know!

The UMBC CSEE Seminar Series Presents

Technical challenges and opportunities
in studying the brain’s network activity

Dr. Hanbing Lu
National Institute of Drug Abuse, NIH

12:00-1:00pm, Friday 25 September 2015, ITE 325b

Brain structures do not work in isolation; they work in concert to produce sensory perception, motivation and behavior. Recent advances in fMRI technology offer the opportunity to investigate brain’s network activity. Data are accumulated suggesting that dysregulations within and between network activity are implicated in a number of neurodegenerative and neuropsychiatric disorders, including Alzheimer’s disease and drug addiction. Despite wide application of this approach in systems neuroscience, the fundamentals of brain network activity remain poorly understood. Animal models permit invasive manipulations and are uniquely advantageous in this regard. In this talk, Dr. Lu will discuss technical challenges and opportunities in studying brain networks by integrating multiple modalities, including MRI, electrophysiological recording, optical and electromagnetic neural modulation.

Dr. Hanbing Lu received his doctorate training in Biophysics at the Medical College of Wisconsin, during which he developed hardware and imaging sequence for functional magnetic resonance imaging (fMRI) in rodents. He is currently a staff scientist in the Neuroimaging Research Branch, National Institute on Drug Abuse, NIH. Dr. Lu pioneered animal models to investigate brain’s large scale networks. Current efforts include integrating multiple modalities to better understand the neurobiology of brain’s network activity

Hosts: Professors Fow-Sen Choa (Sorry, you need javascript to view this email address. ) and Alan T. Sherman (Sorry, you need javascript to view this email address. )

· More talks and directions ·

UMBC Young Explorers providesout-of-school time programming for 1^st-4^th grade students who attend Lakeland Elementary Middle School. 

During the academic year, we follow the 21^st Century Community Learning Center program model, which consists of 30 minutes of homework help, 60 minutes of academic instruction, and 60 minutes of enrichment for 25-weeks. Young Explorers focuses on Reading and Math skills during the academic hour and STEM during the enrichment hour.  The program begins around early October and ends around late April.  Our goal is to provide a safe, nurturing, engaging environment for children, and we strive to strengthen parent and community involvement in the year-round achievement of their students. 

We serve students who are academically struggling, especially in reading and math.  Many of our students are non-native English speakers, predominantly from Central America.  Most of our students are from low-income families.  All of our students – and their families – want to be successful.

This is a paid Fellowship!

Those interested should fill out the attached application and submit it to Zach Pekor, zpekor@umbc.edu. 

Fellow Responsibilities include, but are not limited to:

·         Primary Responsibilities:

o   Facilitate the 30-minute homework help and 60-minute academic blocks of instruction

o   Establish and maintain front-line care and education of program youth

o   Maintain assigned classroom space, which we borrow from teachers

·         Shared Responsibilities:

o   Lead any community meetings, assist and/or lead enrichment activities, and chaperone field trips

o   Oversee volunteers (i.e. transportation, schedule, attendance) and attend Shriver Center site leader meetings

o   Actively participate in community engagement & service learning activities, program meetings, and all Young Explorers training workshops and reflection meetings

A blog reflection from Women’s Center staff member, Carrie Cleveland

I watched the Republican debate twice.  Yes.  That is six hours of my life I spent listening, analyzing, and forming my own opinions about the candidates. I went in with some preconceived notions.  I knew any talk about Planned Parenthood would make me upset because this group of people fail to acknowledge what Planned Parenthood does for women who do not have access to gynecological care.  I was surprised when Donald Trump said he believes we need to spread out the vaccinations that children get because I feel the same way, but I’ll save that post for another day.  I was hoping to see Carly Fiorina carry the torch for  women, but she let me down.

Ms. Fiorina especially let me down when at the end the candidates were asked a “lighthearted” question about having a woman on the ten dollar bill, but so did most of the candidates. Senator Ron Paul chose Susan B. Anthony (yeah!) but then Mike Huckabee said his wife.  Wow.  Not to say anything negative about his wife Janet, but was he so unable to think of ONE woman who did anything for this country? Earlier in the debate he went on and on about ninth grade civics class but clearly Mr. Huckabee needs to spend some time learning about the great women of this country. 

Marco Rubio and Ted Cruz said Rosa Parks.  Ok, I can get behind that, but I wonder if these men know all about what Rosa Parks did over her lifetime.  Not only did she refuse to give up her seat on the bus, but she became a part of the Montgomery Bus Boycott.  Mrs. Parks took her role as a civil rights leader seriously and continued to fight against racial injustice long after the bus boycott was over.  She also championed the causes of women.  Rosa Parks worked as an advocate for black women who were raped by white men.  If Senators Rubio and Cruz knew about all the work this woman did over her lifespan, would they still pick her?

Doctor Ben Carson said his mom.  Now, as a mother, of course I think that is a sweet answer, but again, why not embrace your strong Maryland ties and throw out Harriet Tubman as a suggestion? That might have won him a few votes in this blue state. The first woman to graduate from medical school was Elizabeth Blackwell, but she was British, so not really a option for Dr. Carson.

Donald Trump said his daughter, but then flippantly said Rosa Parks.  It sounded like such a copy cat answer.  There was no heart and thought about his choice.  We all know he loves his plane, he told us it is better than Air Force One.  So maybe Amelia Earhart would have been a good woman for Mr. Trump to suggest.

Jeb Bush.  Oh Jeb.  Margaret Thatcher is pretty cool.  I will give you that, but you needed to suggest an AMERICAN woman.  Are there no strong women leaders in this country that you could have thought of? How about Barbara Jordan, the first black woman in the south to be elected into the House of Representatives. There is also Krysten Sinema.  She is the first openly bisexual woman elected to Congress, but we will have to wait quite a while for Ms. Sinema to be a viable option, as only women who have died are allowed to be considered.

Scott Walker suggested Clara Barton, the founder of the American Red Cross.  I give him a point for thinking on his feet and coming up with someone besides his mom, his wife, Rosa Parks, or Susan B. Anthony. You get a pass this time Governor Walker.

Now we come to Carly Fiorina who said no one.  I think that response made me the most upset. Her comments about not needing to reshape history failed to answer the question.  Let’s honor a woman who made history, who paved a path so you can stand on that stage.  I would suggest she read about Elizabeth Cady Stanton. I felt like Ms. Fiorina really let women down in this moment. Saying that women are not a special interest is simply untrue.  Women are a special interest group both past and present because in the history of this country we have almost always been represented by men (and we still are!).  Yes, we need more women in government, but we also need women who understand that women are marginalized by our gender and our other intersecting identities like race, class, and sexual orientation. We need women who want to help us make up the pay gap for all women, who want to fight for a better maternity leave policy, and who want to make the workplace a more hospitable place for mothers (to name just a few important issues). She sounded like one of the guys which makes me question where her unique voice is.

Governor Kasich suggest Mother Teresa.  Governor, please see my response to Jeb Bush above.

Governor Chris Christie.  Now, I should say, I have a warm spot in my heart for a loud mouth, brash man from New Jersey.  I do not agree with much of his politics, but he reminds me of home.  That said, I was happy that the Governor chose Abigail Adams, not only because she was a kick ass wife who was as much involved in the shaping of this country as her husband, (please watch John Adams, the miniseries for an in-depth look at these two) but she fought for married women to have rights to property in a time when that was unheard of. Governor Christie gets a point for having a great suggestion as an answer to the question.

My final suggestion to all these candidates, many of whom are parents, is to get a book called Heroes for my Daughter.  It is by Brad Meltzer and it is a beautiful book that talks about many different people, many of whom are women, and what amazing things they have done for this world. I think many of you need some education around strong women so that maybe next time someone asks for an example of one, you are prepared.

So, tell me UMBC, who would you like to see on the ten dollar bill?

For more info on the campaign to get a woman on some American dollar bills, check out these links and resources:

Women On 20s
A podcast from Stuff Mom Never Told You: The $10 Woman