TY  - JOUR
A1  - Schlosser, Rainer
T1  - Scalable relaxation techniques to solve stochastic dynamic multi-product pricing problems with substitution effects
JF  - Journal of revenue and pricing management
N2  - In many businesses, firms are selling different types of products, which share mutual substitution effects in demand. To compute effective pricing strategies is challenging as the sales probabilities of each of a firm's products can also be affected by the prices of potential substitutes. In this paper, we analyze stochastic dynamic multi-product pricing models for the sale of perishable goods. To circumvent the limitations of time-consuming optimal solutions for highly complex models, we propose different relaxation techniques, which allow to reduce the size of critical model components, such as the state space, the action space, or the set of potential sales events. Our heuristics are able to decrease the size of those components by forming corresponding clusters and using subsets of representative elements. Using numerical examples, we verify that our heuristics make it possible to dramatically reduce the computation time while still obtaining close-to-optimal expected profits. Further, we show that our heuristics are (i) flexible, (ii) scalable, and (iii) can be arbitrarily combined in a mutually supportive way.
KW  - multi-product pricing
KW  - substitution effects
KW  - data-driven demand
KW  - dynamic
KW  - programming
KW  - heuristics
Y1  - 2020
U6  - https://doi.org/10.1057/s41272-020-00249-z
SN  - 1476-6930
SN  - 1477-657X
VL  - 20
IS  - 1
SP  - 54
EP  - 65
PB  - Palgrave Macmillan
CY  - Basingstoke
ER  - 
TY  - JOUR
A1  - Schlosser, Rainer
T1  - Risk-sensitive control of Markov decision processes
BT  - a moment-based approach with target distributions
JF  - Computers & operations research : and their applications to problems of world concern
N2  - In many revenue management applications risk-averse decision-making is crucial. In dynamic settings, however, it is challenging to find the right balance between maximizing expected rewards and minimizing various kinds of risk. In existing approaches utility functions, chance constraints, or (conditional) value at risk considerations are used to influence the distribution of rewards in a preferred way. Nevertheless, common techniques are not flexible enough and typically numerically complex. In our model, we exploit the fact that a distribution is characterized by its mean and higher moments. We present a multi-valued dynamic programming heuristic to compute risk-sensitive feedback policies that are able to directly control the moments of future rewards. Our approach is based on recursive formulations of higher moments and does not require an extension of the state space. Finally, we propose a self-tuning algorithm, which allows to identify feedback policies that approximate predetermined (risk-sensitive) target distributions. We illustrate the effectiveness and the flexibility of our approach for different dynamic pricing scenarios. (C) 2020 Elsevier Ltd. All rights reserved.
KW  - risk aversion
KW  - Markov decision process
KW  - dynamic programming
KW  - dynamic
KW  - pricing
KW  - heuristics
Y1  - 2020
U6  - https://doi.org/10.1016/j.cor.2020.104997
SN  - 0305-0548
VL  - 123
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Intziegianni, Konstantina
A1  - Cassel, Michael
A1  - Rauf, S.
A1  - White, S.
A1  - Rector, Michael V.
A1  - Kaplick, Hannes
A1  - Wahmkow, Gunnar
A1  - Kratzenstein, S.
A1  - Mayer, Frank
T1  - Influence of Age and Pathology on Achilles Tendon Properties During a Single-leg Jump
JF  - International journal of sports medicine
N2  - Prevalence of Achilles tendinopathy increases with age leading to a weaker tendon with predisposition to rupture. Conclusive evidence of the influence of age and pathology on Achilles tendon (AT) properties remains limited, as previous studies are based on standardized isometric conditions. The study investigates the influence of age and pathology on AT properties during single-leg vertical jump (SLVJ). 10 children (C), 10 asymptomatic adults (A), and 10 tendinopathic patients (T) were included. AT elongation [mm] from rest to maximal displacement during a SLVJ on a force-plate was sonographically assessed. AT compliance [mm/N]) and strain [%] was calculated by dividing elongation by peak ground reaction force [N] and length, respectively. One-way ANOVA followed by Bonferroni post-hoc correction (=0.05) were used to compare C with A and A with T. AT elongation (p=0.004), compliance (p=0.001), and strain were found to be statistically significant higher in C (27 +/- 3mm, 0.026 +/- 0.006[mm/N], 13 +/- 2%) compared to A (21 +/- 4mm, 0.017 +/- 0.005[mm/N], 10 +/- 2%). No statistically significant differences (p0.05) was found between A and T (25 +/- 5mm, 0.019 +/- 0.004[mm/N], 12 +/- 3%). During SLVJ, tendon responded differently in regards to age and pathology with children having the most compliant AT. Higher compliance found in healthy tendons might be considered as a protective factor against load-related injuries.
KW  - children
KW  - tendinopathy
KW  - compliance
KW  - dynamic
KW  - ultrasonography
Y1  - 2016
U6  - https://doi.org/10.1055/s-0042-108198
SN  - 0172-4622
SN  - 1439-3964
VL  - 37
SP  - 973
EP  - 978
PB  - Thieme
CY  - Stuttgart
ER  -