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Welcome to Khodr Shamseddine’s professional web page |
Contributed Talks at Conferences
Invited Talks, Seminars and Colloquia at
Universities
As
the Graduate Program Director in the Department of Mathematics at
My research interests and activities include various areas of non-Archimedean Analysis: power series and analytic functions, measure theory and integration, optimization, existence and uniqueness of solutions of differential equations, complex analysis and multivariable analysis. The focus of my research has been on the Levi-Civita fields which were first introduced by the Italian mathematician Tullio Levi-Civita at the end of the nineteenth century. Of those Levi-Civita fields, one (which we denote by R-script) is of particular interest; it is shown to be the smallest non-Archimedean field extension of the real numbers that admits roots of positive elements and that is complete in the order topology. In fact, R-script is small enough so that the numbers of the field can be implemented on a computer; and this allows for many useful applications, one of which is the fast and accurate computation of the derivatives of real-valued functions up to high orders.
We have studied convergence of sequences and series in two different topologies, which led to an exhaustive study of power series. A handful of people have investigated power series on the Levi-Civita fields before, but all the previous studies were restricted to the special case of power series with real coefficients. We have dropped that restriction and showed that power series on Levi-Civita fields have all the nice smoothness properties that real power series have. In particular, they satisfy the intermediate value theorem and the mean value theorem, they are infinitely often differentiable and they are re-expandable around any point within their domain of convergence.
While it is a known fact that conventional continuity or differentiability are not sufficient to guarantee that a function on a closed interval of a non-Archimedean field be bounded or satisfy any of the common theorems of real calculus, we have shown that under mild conditions, differentiability is sufficient for the function to assume all intermediate values and a differentiable inverse function. We also showed that conventional differentiability is not the right one to study optimization questions on non-Archimedean fields in general; and based on a stronger concept of differentiability, we studied finite-dimensional optimization both with and without constraints. In both cases, we derived necessary and sufficient conditions of first and second order for a function to have a local minimum at a point of its domain.
We have developed a measure theory and integration on the Levi-Civita field R-script. We introduced a measure that proved to be a natural generalization of the Lebesgue measure on the field of the real numbers and have similar properties. Then we introduced a family of simple functions from which we obtained a larger family of measurable functions and derived a simple characterization of such functions. We studied the properties of measurable functions, we showed how to integrate them over measurable sets, and we showed that the resulting integral satisfies similar properties to those of the Lebesgue integral of Real Analysis.
Research currently in progress aims at understanding the topological structure of the non-Archimedean Levi-Civita fields and developing a complete calculus theory on such fields, extending all the common theorems of real calculus. Multivariable analysis and complex analysis on non-Archimedean fields are then two natural research projects to investigate and try to develop. Moreover, now that an integration theory has been achieved, this will lead naturally to investigating a general theory of differential equations on these fields with possible applications in solving differential equations on the field of real numbers. We have developed all the mathematical tools necessary to work on all the projects above, any one of which (or a part thereof) may also constitute a good research project to work on with a graduate student towards an MS thesis or a PhD dissertation.
Like teaching all other subjects, teaching Mathematics requires the instructor's thorough knowledge of the material as well as the skills to transmit that knowledge to the students as efficiently as possible. I believe that well-prepared and well-organized lectures are necessary to achieve that goal. I also believe that teaching Mathematics has an additional component as compared to teaching other subjects; namely, teaching the students how to think in a logical way and how to write clear and rigorous proofs and solutions for problems. I have always stressed that in my teaching.
A fundamental goal in all the courses that I teach is to help my students learn and succeed, and to foster their interest in Mathematics. My lectures, the examples I present in class, the homework problems I assign after each lecture, the quizzes, and the exams all complement each other to achieve the goal stated above. I am available during all my office hours; and I constantly encourage my students to contact me and arrange for other times to come to my office if they need help and they can't make it to the office hours.
For presentation, clear organization and student participation are two of my principal goals. While presenting the material in my low-level courses, I encourage my students to understand the mathematical concepts and master the techniques needed to solve problems through various examples of different levels of complexity. I believe this is more helpful for the students than trying to memorize formulas, equations, or ways to solve specific problems without sufficient understanding of the concepts and techniques involved.
To facilitate the transfer of the information from the instructor to the students, the WWW resources can be very useful and should be taken advantage of. For each of the courses I have taught since Spring 2000, I have designed a web page on which I posted all important announcements related to the course as well as links to the syllabus, homework assignments, quizzes' solutions, exams' solutions and grades. My students find that very helpful as they state in their evaluation forms at the end of each semester.
My syllabi usually state clearly what material would be covered in the course, what the grades would be based on, as well as the dates of all quizzes and exams, my policies on make-ups, and my office
hours. The quizzes are usually based on the homework assignments; and they then prepare the students for the in-class exams. By the end of the semester, the students have access to the solutions for
up to ten quizzes and three one-hour exams on the web pages of each of the courses; and that constitutes excellent review material for the final exam since the problems on the quizzes and exams naturally
cover the main concepts and techniques that I want the students to learn from the course.
Besides having the homework problems and the quizzes as good review material for the exams, I also usually have a full review lecture in class before each of the exams to prepare the students best for the exam, to answer any questions from the students on the material covered on that particular exam, and to do more review problems. Also, to further help the students, I distribute a list of review problems about a week before each exam, including the final exam; then I go over some of those review problems in class and post the answers to all of them on the web.
In the senior level and graduate courses that I teach, I normally put more emphasis on rigor both in my lectures and in my distributed solutions of exams and homework sets (which replace weekly quizzes
in the lower level courses.) I encourage my students to work independently on their homework problems, to acknowledge their fellow students' contribution in case of collaboration, and to widen their interests in Mathematics beyond the classroom through additional reading and attending seminars and colloquia; and I foster my students' appreciation of mathematical research. As the Graduate Program Director, I have succeeded in recruiting several students from the undergraduate courses, who ended up doing very well in the graduate program. Moreover, I have recruited two undergraduate students to work with me on research projects, who later presented their work to the whole Department.
Since my graduation with a dual PhD in Physics and
Mathematics in December 1999, I have been teaching in a Mathematics department
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Teaching at
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Spring
2006 |
Fall 2006 |
Spring
2007 |
Fall 07 |
Spring 08 |
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Math 137 |
Math 133 |
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Math 391 |
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Fall 2003 |
Spring
2004 |
Fall 2004 |
Spring
2005 |
Fall 2005 |
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Math 137 |
Math 137 |
Math 137 |
Math 137 |
Math 137 |
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2007-2008
(WIU) · University Ø University Research Council Ø Evidence of English Proficiency and Minimum TOEFL Requirements Committee · College of Arts & Sciences Ø College of Arts & Sciences Graduate Studies Committee · Department of Mathematics Ø Graduate Committee (Chair) Ø Personnel Committee Ø Curriculum Committee |
2007-2008
(Outside WIU) ·
PhD Committee for Dodzi Attimu ( · Tenth International Conference on P-adic Functional Analysis (June 30-July 3, 2008): o Local Organizing Committee o Scientific Committee |
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2005-2006
· College of Arts & Sciences Ø College of Arts & Sciences Graduate Studies Committee · Department of Mathematics Ø
Graduate Committee (Chair) Ø
Colloquium Committee Ø
Curriculum Committee |
2006-2007
· University Ø University Research Council Ø Evidence of English Proficiency and Minimum TOEFL Requirements Committee · College of Arts & Sciences Ø College of Arts & Sciences Graduate Studies Committee · Department of Mathematics Ø Graduate Committee (Chair) Ø Colloquium Committee Ø Computer Affairs Committee Ø Curriculum Committee |
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2003-2004
· Department of Mathematics Ø High School Relations Committee Ø Library Committee (Chairman) Ø Upper Division Curriculum Committee Ø Javed Siddique’s MS thesis committee Ø Duygu Inceoz’s MS thesis committee |
2004-2005
· Department of Mathematics Ø Graduate Committee (Chair) Ø
Colloquium Committee Ø
Curriculum Committee Ø Upper Division Curriculum Committee |
As the Chairman of the Graduate Committee since Fall 2004, I have led the efforts of that committee in recruiting new graduate students and advising new and current graduate students as well as assisting the Department Chair with various matters pertaining to the graduate program. I have also led the efforts of the Graduate Committee in preparing the proposals for revisions in the graduate program including new structure, courses and tracks to better serve the needs of our incoming graduate students. I have gathered ideas, thoughts and suggestions from the various groups in the Department about the structure and the contents of the courses in the revised program and designed a web page for that purpose to facilitate the discussions and the exchange of ideas in the Department. As a result, proposals for a revised program have been submitted and approved by the Dean and the Graduate Council; and the revised program has started in Fall 2006.
Maintained by K. Shamseddine (last updated on 7/10/07). Top of page