Subject
Time and frequency have a privileged role in physics and applications because they are the most precisely measured physical quantities. The wrist watch, for example, is the only artifact accurate within 1E-5 - 1E-6 at a cost affordable to all consumers. Atomic clocks exhibit the amazing accuracy of 1E-15, and a stability better by a factor 10. Though the accuracy of 1E-15 relates only to fundamental physics and metrology, short term stability is a major concern in telecommunications, space applications and radars.
Traditionally, frequency stability is measured in the time domain and described using wavelet variances known as the Allan variance sigma_y^2(tau) and its modified versions. The variable tau is the measurement time. The stability depends on the measurement time in the same way of a balance, which is less “precise” when the mass to be measured is very different from 1 kg.
The estimation of sigma_y^2(tau) and of its confidence is well documented in the literature available in the past 20 years. Conversely, the spectral analysis of oscillators is still an empirical domain, in which results are usually given as a raw power spectral density of the phase noise, i.e., Sphi(f) ou L (f). Analysis seldom goes beyond the identification of the interference from the mains power supply (50 or 60 Hz et harmonics) and the identification of two-three fundamental types of noise. This approach is no longer suitable to the needs of emerging technologies.
This is a new domain. Hence, the minimum target is reasonably low: to adapt established spectral-analysis methods to the oscillator and to identify the oscillator’s stochastic phenomena. Nonetheless, this is a great opportunity for a smart student, as he can innovate in the interpretation of the oscillator physics and in the measurement methods and achieve outstanding experimental results. A side branch is the improvement of the measurement accuracy, which is currently of 2 dB in primary laboratories. The bulk of the expected work is about the statistical analysis of phase noise spectra. Besides, the student will achieve a deep understanding of oscillators and of experimental techniques.
University and laboratory
Ph.D. scholarship is managed by the University of Franche Comt’e, Besançon, France. The work site is the Time and Frequency Dept. of the FEMTO-ST Institute, affiliated to the University of Franche Comt’e, Besançon. This department, merging the laboratory of chronometry (LCEP) and the laboratory of physic and metrology of oscillators (LPMO), issues from the Laboratoire de l’Horloge Atomique, funded by the Nobel prize Alfred Kastler. The T&F Dept. is the world leader in the domain of the measurement of the oscillator noise. Besides, this department is the european leader in the domain of ultra-stable oscillators and chip-scale atomic clocks.
Candidate profile
The best student for this subject is fond to computer programming and calculus, and eager to learn sophisticated experimental methods of electronics. He is motivated by the will of learning and by the investment on his future life. In the longer term, he would like to do applied research in academic institutions or industry, or high-tech engineering, preferably in international environment.
Advisors
During his Ph.D., the student will be advised by E. Rubiola (2/3-3/4), full professor, and by F. Vernotte (1/4-1/3), full professor and head of the Observatory of Besançon.
Stipend
The student will receive a stipend from the French ministry of education for three years, as ruled by the French government. The candidate must fill two conditions
1. age 29 years max,
2. university degree “Master 2″ (5 year university degree) or equivalent, obtained in 2008. The equivalence is managed on site.
Candidates unaware of the French education system should know that: tuition are very small or zero, and the stipend is generally sufficient for a modest yet quite reasonable life standard.
Contact
e-mail: rubiola[ at ]femto-st.fr
home page http://rubiola.org
Thursday, October 2, 2008
Wednesday, October 1, 2008
USA: The Post-doctoral Fellowship of the Committee on Global Thought at Columbia University
Post doctoral Fellowship
The post-doctoral fellowship of the Committee on Global Thought at Columbia University is designed to bring together an innovative group of interdisciplinary researchers from around the world. The Fellowship gives emerging scholars the opportunity to work with distinguished faculty and provide a space for collaborative research and publication. CGT encourages interdisciplinary, transnational research under three broad themes: Secularism and Diversity, Global Governance, and Poverty and Inequality. Past fellows have researched topics including the local socio-economic consequences of global policy, the historical roots of identity, and the evolution of transnational and international political structures. Scholars from any discipline may apply, provided that they successfully indicate how their work will contribute to CGT’s three research themes listed above. Up to four fellowship spots are available for the academic year beginning August 1, 2009.
The term of the fellowship is one calendar year, beginning August 1, 2009 and ending July 31, 2010. The fellowship is renewable for an additional year, contingent upon mutual satisfaction with demonstrated progress.
Requirements
Fellows are expected to:
Teach or assist with one undergraduate or graduate course, either of their own design or as specified by the Committee. When teaching, fellows are required to hold weekly office hours.
Participate in planning and execution of research workshops and symposia.
Present their individual research projects once a semester.
Eligibility
International applicants are encouraged to apply. If selected, Columbia University will sponsor the appropriate visa.
Candidates will be considered only if:
They received their first doctorate from a recognized university no earlier than August 1, 2004 (Those who have not completed their degree at the time of application must have submitted their dissertation for defense on or before April 1, 2009. Evidence required, no exceptions).
They do not hold or have not held a tenure or tenure-track position.
They can fluently speak, publish, and teach in English.
They submit an original research proposal. An adaptation of a dissertation or previous publication does not qualify.
Benefits
Fellows will receive:
An annual salary of $55,000, which includes health insurance and other standard benefits.
Access to Columbia University libraries and computer resources.
Shared office space.
Eligibility for additional funding for special research projects.
Eligibility to apply for campus housing.
Application Checklist- all items must be completed and postmarked by December 1, 2008 and received by December 10, 2008.
Send materials to:
Committee on Global Thought
3 Claremont Ave. Suite 101
New York, NY 10027
attn: Post-doc Search
An official graduate school transcript and terminal diploma if received (provide English translation if necessary).
Three (3) letters of reference.
Application fee of $30 USD. Check or money order made payable to Columbia University (Fee may be waived at our discretion).
Please send 5 copies of the following:
1.Curriculum Vitae
2. Cover Letter
3. Research proposal
-not to exceed 1500 words;
-The description should include the background, nature, importance, specific objectives, and methodology of the proposed research project
4. Writing Sample
- not to exceed 20 double spaced pages
- preferably an article or research paper published in a scholarly journal
- topic should be pertinent to the proposed research project
- no books will be accepted
5. Syllabus of proposed course or Outline of proposed Symposium
All materials must be in English; translations accepted.
NO MATERIALS, INCLUDING RECOMMENDATION LETTERS, WILL BE ACCEPTED VIA EMAIL.
Applications are reviewed immediately, so please ensure they are complete. Applications received piecemeal are not likely to be assembled or read.
All questions may be directed to: cgtmail[ at ]gmail.com.
http://cgt.columbia.edu/docs/Jobs
The post-doctoral fellowship of the Committee on Global Thought at Columbia University is designed to bring together an innovative group of interdisciplinary researchers from around the world. The Fellowship gives emerging scholars the opportunity to work with distinguished faculty and provide a space for collaborative research and publication. CGT encourages interdisciplinary, transnational research under three broad themes: Secularism and Diversity, Global Governance, and Poverty and Inequality. Past fellows have researched topics including the local socio-economic consequences of global policy, the historical roots of identity, and the evolution of transnational and international political structures. Scholars from any discipline may apply, provided that they successfully indicate how their work will contribute to CGT’s three research themes listed above. Up to four fellowship spots are available for the academic year beginning August 1, 2009.
The term of the fellowship is one calendar year, beginning August 1, 2009 and ending July 31, 2010. The fellowship is renewable for an additional year, contingent upon mutual satisfaction with demonstrated progress.
Requirements
Fellows are expected to:
Teach or assist with one undergraduate or graduate course, either of their own design or as specified by the Committee. When teaching, fellows are required to hold weekly office hours.
Participate in planning and execution of research workshops and symposia.
Present their individual research projects once a semester.
Eligibility
International applicants are encouraged to apply. If selected, Columbia University will sponsor the appropriate visa.
Candidates will be considered only if:
They received their first doctorate from a recognized university no earlier than August 1, 2004 (Those who have not completed their degree at the time of application must have submitted their dissertation for defense on or before April 1, 2009. Evidence required, no exceptions).
They do not hold or have not held a tenure or tenure-track position.
They can fluently speak, publish, and teach in English.
They submit an original research proposal. An adaptation of a dissertation or previous publication does not qualify.
Benefits
Fellows will receive:
An annual salary of $55,000, which includes health insurance and other standard benefits.
Access to Columbia University libraries and computer resources.
Shared office space.
Eligibility for additional funding for special research projects.
Eligibility to apply for campus housing.
Application Checklist- all items must be completed and postmarked by December 1, 2008 and received by December 10, 2008.
Send materials to:
Committee on Global Thought
3 Claremont Ave. Suite 101
New York, NY 10027
attn: Post-doc Search
An official graduate school transcript and terminal diploma if received (provide English translation if necessary).
Three (3) letters of reference.
Application fee of $30 USD. Check or money order made payable to Columbia University (Fee may be waived at our discretion).
Please send 5 copies of the following:
1.Curriculum Vitae
2. Cover Letter
3. Research proposal
-not to exceed 1500 words;
-The description should include the background, nature, importance, specific objectives, and methodology of the proposed research project
4. Writing Sample
- not to exceed 20 double spaced pages
- preferably an article or research paper published in a scholarly journal
- topic should be pertinent to the proposed research project
- no books will be accepted
5. Syllabus of proposed course or Outline of proposed Symposium
All materials must be in English; translations accepted.
NO MATERIALS, INCLUDING RECOMMENDATION LETTERS, WILL BE ACCEPTED VIA EMAIL.
Applications are reviewed immediately, so please ensure they are complete. Applications received piecemeal are not likely to be assembled or read.
All questions may be directed to: cgtmail[ at ]gmail.com.
http://cgt.columbia.edu/docs/Jobs
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