2,519 research outputs found
Optimal Management of DC Pension Plan with Inflation Risk and Tail VaR Constraint
This paper investigates an optimal investment problem under the tail Value at
Risk (tail VaR, also known as expected shortfall, conditional VaR, average VaR)
and portfolio insurance constraints confronted by a defined-contribution
pension member. The member's aim is to maximize the expected utility from the
terminal wealth exceeding the minimum guarantee by investing his wealth in a
cash bond, an inflation-linked bond and a stock. Due to the presence of the
tail VaR constraint, the problem cannot be tackled by standard control tools.
We apply the Lagrange method along with quantile optimization techniques to
solve the problem. Through delicate analysis, the optimal investment output in
closed-form and optimal investment strategy are derived. A numerical analysis
is also provided to show how the constraints impact the optimal investment
output and strategy
Geometric accounts of consonant-vowel interactions in developing systems
Phenomena associated with consonant-vowel interactions are examined relative to three general models of feature geometry which differ in the planar relationship of consonants and vowels. The data come from reports of developing phonological systems, both normal and disordered. Geometric analyses reveal that consonants and vowels are fully integrated in the earliest stages of development such that the place specification of consonants is primarily derived from the vowel. However, change through development requires modifications either in the principles of place association, the degree of feature specification, or the planar representation of consonants and vowels.National Institutes of Health DC00433, RR7031K, DC00076, DC001694 (PI: Gierut)This is an Accepted Manuscript of an article published by Taylor & Francis in Clinical Linguistics & Phonetics on January 1993, available online: http://wwww.tandfonline.com/10.3109/02699209308985559
Emergent order in the spin-frustrated system DyxTb2-xTi2O7 studied by ac susceptibility measurements
We report the a.c. susceptibility study of Dy_xTb_{2-x}Ti_2O_7 with x in [0,
2]. In addition to the single-ion effect at Ts (single-ion effect peak
temperature) corresponding to the Dy3+ spins as that in spin ice Dy_2Ti_2O_7
and a possible spin freezing peak at Tf (Tf < 3 K), a new peak associated with
Tb^{3+} is observed in at nonzero magnetic field with a
characteristic temperature T^* (Tf < T^* < Ts). T^* increases linearly with x
in a wide composition range (0 < x < 1.5 at 5 kOe). Both application of a
magnetic field and increasing doping with Dy3+ enhance T^*. The T^* peak is
found to be thermally driven with an unusually large energy barrier as
indicated from its frequency dependence. These effects are closely related to
the crystal field levels, and the underlying mechanism remains to be
understood.Comment: 7 pages, 5 figure
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