Nabin K. Malakar, Ph.D.

NASA JPL
I am a computational physicist working on societal applications of machine-learning techniques.

Research Links

My research interests span multi-disciplinary fields involving Societal applications of Machine Learning, Decision-theoretic approach to automated Experimental Design, Bayesian statistical data analysis and signal processing.

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Interested about the picture? Autonomous experimental design allows us to answer the question of where to take the measurements. More about it is here...

Hobbies

I addition to the research, I also like to hike, bike, read and play with water color.

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Sunday, July 13, 2014

An Interview with Dr. Churamani Gaire

Dr. Churamani Gaire, from Syangja, Nepal,  shares fond memories of the school days, teachers and mentors. He also shares his experience in joining the semiconductor industry as he is currently working as Principal Process Engineer at GLOBALFOUNDRIES.  It is our pleasure to have him in my frame of reference.

Could you please tell us a little bit about yourself.
I was born and raised in an economically subaltern farming family in Kuwakot-8, Syangja. I went to local school (Now Bhanu Higher Secondary School, Chaughera, Syangja), where I learned Nepali and English alphabets from my teachers Durga Pangeni and Hari Bdr Ale, respectively. I completed high school from Keware (Now Bal Siddha Higher Secondary School), Syangja. I then continued my undergraduates at Prithvi Narayan College, Pokhara and Masters in Physics at Tribhuvan University, Kirtipur. Having to answer this question makes me a bit nostalgic of all the fond memories.
My research interest is in the nanotechnology. My professional profile is in LinkedIn: https://www.linkedin.com/pub/churamani-gaire/1a/45a/2a1
My research activities are disseminated in various journals and conference proceedings and are available for public consumption: http://scholar.google.com/citations?user=fY905A4AAAAJ&hl=en&oi=ao.
How did you decide to study physics? Did anyone, in particular, influence you?
I was shy as a child and did not know what I was up to. Growing up, I used to carve tops and toy cars out of wood and play. By high school time, it was clear to me that I was more into mathematics and physical sciences than other subjects. I was privileged to have great teachers like Bhoj Raj Gurung and Babu Ram Sharma in High School, Namo Narayan Yadav, Pabitra Mani Poudel and Binay Kumar Jha in Undergraduates; Devendra Raj Mishra and Shekhar Gurung in my Masters. I have the highest regard to Babu Ram Sharma, Binay Kumar Jha and Shekhar Gurung for their support I got during my high school and college times. While I recall these great names today, it is Guru-Purnima, and I salute these great teachers and mentors on this occasion.
What strategies did you use to be successful in college? Please give out some tips on how to become a successful student in Nepal?
My strategy was to attend all the classes, go through the subject material more than once, note down the areas of weakness and focus on those items in the next iteration of study. In my opinion, one has to develop his/her own style. There is no universally applicable strategy per se. However, my biggest tip to the Nepalese students would be to not waste their time by going to political pep-rallies and become puppets of political parties.
Could you also describe your academic and research journey in USA? What are the challenges for Nepalese students?
I started my graduate study from University at Albany in theoretical physics. I later transferred to Rensselaer Polytechnic Institute (RPI), due to a better match to my academic interest. I conducted my graduate research in nanoscale growth and characterization of semiconducting materials. After my graduation, I continued my research at RPI and developed strategy to grow near single crystal semiconductor material starting from amorphous substrate suitable for low-cost energy application. 
As regard to the challenges, it's the initial first few months when one is trying to adjust with so many new things: new place, new education system and some language barrier. Back in the country, our focus was more on theoretical than experimental physics. So, if you want to pursue theoretical physics in USA, I think you can immediately choose a research group and start contributing towards your graduate dissertation. However, if you want to pursue experimental physics, it takes one-to-two semesters before you can contribute towards your graduate dissertation. Again, it varies from person to person. I believe that Nepalese graduates are capable of competing with international graduates.
Could you please suggest the practical applications of your research outcomes? Do you have a favorite research paper (written by yourself or somebody else)?
My research was about nano-heteroepitaxial growth of near single crystal semiconductor material starting from amorphous substrate. This is applicable in substrate fabrication for low-costing solar cells. I use epitaxial growth method in my current job to create individual transistor units used in computer chips. My publications done during my graduate school are in the public domain and are available for your viewing pleasure as I mentioned earlier. Instead of me saying which of my articles I like, I will leave that option to the public to judge. However, I shall say some of my papers are cited more than the others by the researchers in the field.
How is your experience in joining the Industry? Was there any culture shock for an academician? Or shall a PhD holder expect any difference?
Definitely there is a bit of culture shock. I find rather interesting differences in academia and high-tech industry. Industry has more stringent requirements for deadlines. Your decisions can make immediate financial impact on the order of 10s of millions of dollars. To this end, I would say both the risk and reward are much higher in the high tech industry. And whether you have a PhD or not does not make much difference in the industry, your abilities are judged through whether you can solve problems efficiently and precisely and deliver the solution or not. Nevertheless, the rigorous training process that you have gone through during your PhD definitely prepares you for the rigorousness required in the industry.
A general perception is that industry experience is very demanding. Could you please give us a snapshot of your one day in office?
Yes, you are correct that the industry is very demanding due to short shelf-life of technology. One has to constantly update the new things that are in the market, and stay up to date with the technology challenges and solutions.
I work in semiconductor foundry and own a critical process responsible for transistor performance. On my typical day, I have to fulfill three kinds of major responsibilities and generally attend/prepare for 5-6 meetings a day to:
  • Ensure that there are no problems in my process step from both process and hardware aspects. If there are problems, resolve immediately.
  • Ensure that internal and external customer demands are met. Internal customers include integration and device team who are constantly looking for new processes and recipes to improve the overall flow. The external customers are real customers who I have to engage time to time and ensure they are comfortable working with us.
  • Ensure that we offer improved process to our internal and external customers. We constantly conduct experiments to improve our process. We analyze/interpret data and feed-forward the learning to next cycle, a process we call “continuous improvement process”. 
What have you found to be the toughest aspect of being a physicist, if any?
The job hunting was the toughest part as a physicist.
Which of the skills are strongly recommended for the job hunters in this field?
In my opinion, strong communication skill, data analysis/interpretation and decision making ability are some of the key items recruiters are looking in new hires.
Sir, since I am not a professional interviewer, would you like to add anything else? Thank you for your time!
I am afraid your questions are more professional than my answers. I commend you for your effort. And I wish you for your continuous success as blogger in the future. Thanks very much.

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Tuesday, July 1, 2014

An Interview with Dr. Dipak Rimal


Dr. Dipak Rimal recently defended his PhD in experimental nuclear physics, and joined a post-doctoral research associate position at the University of Florida. He was born and raised in Baigundhura VDC in south-eastern part of Nepal. We are pleased to have Dr. Rimal in my frame of reference!



Please tell us about yourself, and your journey to USA for higher education.
I was born and raised in Baigundhura VDC in south-eastern part of Nepal. My father was a local educator, and had a great appreciation for science and technology. His constant motivation and inspiration lead me to pursue higher education in science. After passing the School Leaving Certificate (SLC) exam from Shree Amar Madhyamik Vidhyalaya in 1995, I went to Birat Science College, Biratnagar to study science (I. Sc.). I then went to Tri-Chandra College for Bachelor's degree. Since I graduated as a physics major with minor in chemistry and math, I got admitted to the Central Department of Physics (CDP), Tribhuvan University for M. Sc. in Physics. After graduating, I taught undergraduate level physics courses at Xavier Academy, Lazimpat for two years. In the fall of 2007, I moved to Miami after I got admitted into the PhD program at the Department of Physics at Florida International University. I recently graduated from FIU with PhD in physics specializing in experimental nuclear physics.
Could you please describe your PhD research in plain English. (Einstein once said, “If you can't explain it simply, you don't understand it well enough.”)
My PhD research was in the field of experimental nuclear physics. My research was primarily focused on expanding our understanding of the electromagnetic (EM) form factors of the proton, the positively charged core of the hydrogen atom. The EM form factors of the proton are the most fundamental observables, which encode information about the charge and magnetization distribution inside it. Even though the proton has been studied for several decades, a lot remains to be understood about the electromagnetic form factors in order to completely understand the structure of the proton. A significant discrepancy exists between the results from unpolarized and polarized electron scattering measurements of the EM form factors. This discrepancy casts a serious doubt on our understanding of the proton electromagnetic form factors and also on several other observables derived from these form factors (for e.g. proton charge radius). I don’t want to go into details here but plausible theoretical explanations for the cause of this discrepancy have been proposed. Rigorous experimental tests are necessary to make a definitive statement about these explanations. In short, my research was focused on the experimental test of the proposed theoretical explanations.Our team produced an intense matter/anti-matter mixed beam (electron/positron) from a 5.6 GeV primary electron beam at Jefferson Lab. Ordinarily, the matter and anti-matter particles would annihilate releasing the energy in the form of photon. To keep the particles intact, the electrons and positrons were spread over a distance of a few centimeters. The mixed matter/anti-matter beam was then scattered from a liquid hydrogen target, kept at the center of a giant spectrometer known as CEBAF Large Acceptance Spectrometer (CLAS). The elastically scattered electron, positron, and the proton were detected in CLAS. The detected particles were then analyzed to compare the positron-proton and electron-proton interactions.
What are the social applications of your research/ short-term or long-term impact of your research to the society.
My research, being a fundamental science research, may not have immediate social applications. However, in the long run it will reshape the way the electron scattering data is analyzed. My research was intended to test theoretical explanations for the discrepancy between different methods of measuring the charge distribution inside proton. These results will help make a definitive statement about the explanation for a decade long scientific puzzle.
How was your graduate school experience? (Specifically skill(s) you needed to sharpen etc.)
My graduate school experience at FIU has been memorable one. Since we had a lot of fellow Nepali graduate students in the department, the physics department at FIU felt like a second home. I feel lucky that I had an excellent advisor who provided me an opportunity to work in a large international collaboration comprising of scientists from all over the world. I had to learn UNIX/LINUX operating systems, and learn programming languages. I also had to sharpen my problem solving and experimental skills.
Please share few useful tips that you wish you were told when you applied for PhD.
I wish I had learned at least one programming language before I applied for PhD. I wish I was told to learn problem-solving rather than memorizing physics derivations.
Where do you want to be in the next 5 years? What are your hobbies, and spare time activities?
Umm! This one is the hardest one. I don’t really know! I just started working as a post-doctoral research associate at University of Florida. I will be working on MINERvA neutrino experiment at Fermilab to investigate neutrino-nucleus interactions. Let’s see how next 5 years unfold but I definitely want to see myself in a pretty good shape in terms of research. Regarding hobbies, I enjoy visiting new places. I follow world news to keep myself up to date with the recent happenings around the globe. I am also a big time sports fan. In the spare time, I enjoy watching professional leagues and college sports.

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Monday, June 30, 2014

Monitoring in-situ PM2.5 in NYC metro area using #matlab #trendy

Matlab's Trendy feature can be used to monitor and collect hourly air quality station data directly from the source url. The data can be feed into the trendy app using the urlfilter and updatetrend commands.

Here is the basic code that gets the job done for the CCNY location. If you are interested to get multiple data, just append it to the update trend array:
% Get the data from CCNY, update the trendy
url = 'http://www.dec.ny.gov/airmon/stationStatus.php?stationNo=73';
count = urlfilter(url, 'PM25C'); % reading
PMccny = count; % PM at CCNY
updatetrend([PMccny]);
The Trendy then can be used to plot the gathered data. I had to let it gather data for few days before I could plot some nice trends. You can already see the diurnal variation in the data below.
PM2.5 trend in NYC. If the image is not available, follow the link below.

http://www.mathworks.com/matlabcentral/trendy/plots/1349
The plots can be made with the following code (the time and data will be different for your code):
% PM2.5 hourly measurements in CCNY
%   time vector is: time2322
%   data vector is: data2322
plot(time2322,data2322, 'o-');
datetick
hleg = legend('PM2.5(ug/m3)', 'Location', 'SouthWest');
set(hleg, 'FontSize', 8);
title('Air Quality at CCNY station');
I can also set up an email alert if the PM2.5 reading gets higher than some threshold, say 35ugm/m3. Now you can think about the useful applications of such tools!!

Update: well, it has been deprecated! and replaced with "trendy"

Thursday, June 19, 2014

An Interview with Dr. Amit Dongol

Born and raised in Biratnagar, Nepal, Dr. Amit Dongol recently defended his PhD from Physics Department at University of Cincinnati, OH, USA. He will be starting a new job in INTEL from next month.   We present a brief chat with Dr. Dongol. He can be reached on LinkedIn at www.linkedin.com/in/amitdongol/, and also maintains a nice personal website www.amitdongol.com .


0. Could you please tell us a little bit about yourself.
I was born and raised in Biratnagar, Nepal. I had my SLC exam from Jaycee Bal Sadan, Biratnagar, Nepal. For higher studies (I.Sc and B.Sc physics) I went to Mahendra Morang Adarsha Multiple Campus at Biratnagar. I did my Master in Physics from Tribhuvan University, Kirtipur, Nepal. I was also actively involved in family business of photography and I love taking pictures.Recently I have also reviewed a LabView book for Packt Publication. It is a nice book if anyone is interested in learning and building a research lab for software and hardware automation. The name of a book is LabView Graphical Programming Cookbook authored by Yik Yang.

1. How did you decide to study physics?  Did anyone, in particular, influence you?
Being good in math, logical thinking and electronics/computer made me decide to study physics. My elder brother (Raja Dongol) helped me to figure out what to study further in the area of my interest.

2. Could you also describe your academic and research journey in USA? What are the challenges for Nepalese students?
I came to USA with my Wife (Pooja Shrestha). She got her admission for PhD at University of Cincinnati. Soon after one year I also joined a PhD program at University of Cincinnati and got through qualifier exam immediately and joined a research group in computational biophysics. I worked for about one year in the field studying proteins using coarse-grain GO-model. After that I started working in experimental condensed matter physics in the field of nonlinear optics and completed my PhD..The challenges depend upon the individuals, how serious and how well he/she prepares for the challenges. Nothing is impossible, just need to have positive thinking and positive doing blended with hard working and always willing to learn and adapt the situation. If the (TU) courses were to be slightly modified with problem solving strategies and more like real practical problem solving, it would be very helpful to prepare ourselves for education system abroad. It also helps better in cognitive thinking. The challenges are also rewarding.  

3. Could you please describe your thesis in plain English?
My research is mainly focused on characterizing a quantum well sample using femtosecond pulsed laser. The technique I used is called Four-Wave Mixing (FWM) process that involves at-least two or more pulsed laser. The main goal of the research is to study the exciton, electron grating, and exciton grating formed in a quantum well responsible for fast responsive and highly sensitive real-time holographic imaging.

4.  Could you please suggest the practical applications of your research outcomes? Do you have a favorite research paper (written by yourself or somebody else)?
My research goal is to characterize and optimize the II-VI/III-V quantum well sample for the purpose of Real-time holographic imaging called Optical Coherence Imaging (OCI). The potential of the OCI is to image an object concealed behind the turbid media and sensitive enough to image a few 10’s of micron sized object or living organism.

5. Which of the skills are strongly recommended for the job hunters in this field?
I would say learn everything that you could and there is nothing that you should not learn. If you get an opportunity to learn then don’t let it slide. Good experimental hands (if you are experimentalist) and clever logical thinking (for computational programming) with depth knowledge of the subject and instruments is always required. If you are an experimentalist then you should learn one of the hardware controlling softwares. I would recommend LabView because it is one of the most widely used software where you can make your own software or whole package of applications integrating multiple tools and devices together according to your need of your research. This will really boost your resume and lots of job requires the knowledge of this software. For computational people there are so many things around. It does not matter what you do in the field but atleast you need to have commanding knowledge in at-least one or more programming language like, C, C++, C#, perl, Gromacs, Mathematica, Matlab  and many more. Now a days CUDA (a GPU) programming is one of the most rising and demanding to my knowledge. I would recommend it to have this knowledge and skills. I wouldn't say that this is enough but if you can and opportunity provides then learn everything you can. In my case addition to these being able to design and build a website for my research group and making a file server and maintaining also helped me to impress my job interviewer. Being active in social and community services also adds up. There is no one factor but its a whole package I would say.


6. Would you like to add anything else?
Learn whatever you can and its never late to start new things. There is a saying in our society “नजाने गाँउको बाटो नसोध्नु” and I believe this is completely wrong.

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Tuesday, June 17, 2014

PM2.5 and O3 dense ground observation in NYC summer

My research involves use of in-situ data, satellite remote sensing data infused with the meteorological information, and application of machine learning techniques to obtain improved estimates of PM2.5. Broadly, my current project involves climate and air quality research, and I have worked with wide variety of model and remote sensing data.

This post is concerned about the dense urban observation in the summer database collected over the New York City over the years 2009-2012.
This database gives insights into the PM2.5 and O3 concentration in the urban setting. Specifically for New York City where these pollutants can affect about 8 million people. Two figures from summer 2010 are presented below showing the relative concentrations in reference to the background EPA measurements binned over the 15-day measurement period. The densely populated area show increased PM2.5 (ug/m3), while decreased O3 concentrations (ppb).  Some interesting geo-chemistry going on!