Page 36 - Undergraduate Research Opportunities Program Proceedings 2017-18

School of Science
Department of Mathematics

Lagrangian coherent structure (LCS) is a useful concept to understand element transport in a fluid flow. Having the
velocity-field data, the LCS approach can be used to predict the future movement of the particles in a flow and forecast
the shape of the adverted particle. This technique can be used to estimate the contaminated area in an oil spill in ocean
or in volcano ash in the air. To obtain such a LCS, a mathematical tool so called the finite-time Lyapunov exponent (FTLE)
is used. This report aims to study the concepts used in these mathematical tools and replicate a commonly used double
gyre example to illustrate their application. Moreover, the multiscale method is also studied in this report. Some of its
advantages and applications are also discussed in this report.

Prediction of Utility Value for Joint Health States

Supervisor: WONG Man Yu / MATH
Student: ZHANG Tina Danting / MATH Course: UROP1100, Fall

The topic of suicide has been well discussed in phycology and sociology since Durkheim’s keystone theory of suicide
(1897), where it’s seen as mental abnormalities or result of social integration and regulation. Only after a century,
economists started looking at suicide formally with Hamermesh’s Economic Theory of Suicide. Studies that look at
suicide from decision making angle, in comparison to those from social angle, is inadequate. This report discusses three
explanatory factors for suicide in China: income, financial crisis, and availability of method of suicide. For each, along
with some literature review, I present why this factor is important, how we might capture its effect on suicide rate, and
what problems/difficulties are seeking for solutions.

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