排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Walter J. Gutjahr Stefan Katzensteiner Peter Reiter Christian Stummer Michaela Denk 《Central European Journal of Operations Research》2008,16(3):281-306
This paper presents a new model for project portfolio selection, paying specific attention to competence development. The
model seeks to maximize a weighted average of economic gains from projects and strategic gains from the increment of desirable
competencies. As a sub-problem, scheduling and staff assignment for a candidate set of selected projects must also be optimized.
We provide a nonlinear mixed-integer program formulation for the overall problem, and then propose heuristic solution techniques
composed of (1) a greedy heuristic for the scheduling and staff assignment part, and (2) two (alternative) metaheuristics
for the project selection part. The paper outlines experimental results on a real-world application provided by the E-Commerce
Competence Center Austria and, for a slightly simplified instance, presents comparisons with the exact solution computed by
CPLEX. 相似文献
2.
Walter J. Gutjahr Stefan Katzensteiner Peter Reiter Christian Stummer Michaela Denk 《European Journal of Operational Research》2010
This paper develops a multi-objective optimization model for project portfolio selection taking employee competencies and their evolution into account. The objectives can include economic gains as well as gains expressed in terms of aggregated competence increments according to pre-defined profiles. In order to determine Pareto-optimal solutions, the overall problem is decomposed into a master problem addressing the portfolio selection itself, and a slave problem dealing with a suitable assignment of personnel to the work packages of the selected projects over time. We provide an asymptotic approximation of the problem by a linearized formulation, which allows an efficient and exact solution of the slave problem. For the solution of the master problem, we compare the multi-objective metaheuristics NSGA-II and P-ACO. Experimental results both for synthetically generated test instances and for real-world test instances, based on an application case from the E-Commerce Competence Center Austria, are presented. 相似文献
3.
4.
E. Ballestero M. Günther D. Pla-Santamaria C. Stummer 《European Journal of Operational Research》2007
In modern portfolio theory, it is common practice to first compute the risk-reward efficient frontier and then to support an individual investor in selecting a portfolio that meets his/her preferences for profitability and risk. Potential flaws include (a) the assumption that past data provide sufficient evidence for predicting the future performances of the securities under consideration and (b) the necessity to mathematically determine or approximate the investor’s utility function. In this paper, we propose a methodology whose initial phase filters portfolios that are inefficient from a historical perspective. While this is consistent with traditional approaches, the second phase differs from the standard approach as it uses a decision table constructed by considering multiple scenarios assuming strict uncertainty. The table cells measure consequences by a multi-criteria linear performance index of simulated future returns, which avoids difficulties with performance ratios. The real world applicability is illustrated through two studies based on data from the stock exchanges in Frankfurt and Vienna. 相似文献
5.
6.
Sonderegger-Wakolbinger Lea M. Stummer Christian 《Central European Journal of Operations Research》2015,23(2):459-477
Central European Journal of Operations Research - Experimenting with multi-channel operations in reality is both costly and risky, because it can severely affect a firm’s revenues,... 相似文献
7.
Herbert Dawid Reinhold Decker Thomas Hermann Hermann Jahnke Wilhelm Klat Rolf König Christian Stummer 《Central European Journal of Operations Research》2017,25(1):203-230
Smart products not only provide novel functionalities, but also may establish new business models, markets, or distribution channels, strengthen relationships with consumers, and/or add smart remote services. While many technical obstacles of such products have already been overcome, the broad market dissemination of smart products still poses some vital managerial challenges for decision makers. In this paper, we outline the technical potential and future trends of smart consumer products, discuss economic challenges in four scopes, namely, preference-based new product development, market analysis, supply chain design, and industry development, and, in particular, we highlight research perspectives for management science in this promising field. 相似文献
8.
Bomze Immanuel Dörner Karl F. Hartl Richard F. Leopold-Wildburger Ulrike Pflug Georg Rauner Marion Stummer Christian Tragler Gernot Wakolbinger Tina 《Central European Journal of Operations Research》2018,26(2):259-263
Central European Journal of Operations Research - 相似文献
9.
10.
Bioorthogonal click reactions are powerful tools to specifically label biomolecules in living cells. Considerable progress has been made in site-specific labeling of proteins and glycans in complex biological systems, but equivalent methods for mRNAs are rare. We present a chemo-enzymatic approach to label the 5’ cap of eukaryotic mRNAs using a bioorthogonal photoclick reaction. Herein, the N7-methylated guanosine of the 5’ cap is enzymatically equipped with an allyl group using a variant of the trimethylguanosine synthase 2 from Giardia lamblia (GlaTgs2). To elucidate whether the resulting N2-modified 5’ cap is a suitable dipolarophile for photoclick reactions, we used Kohn–Sham density functional theory (KS-DFT) and calculated the HOMO and LUMO energies of this molecule and nitrile imines. Our in silico studies suggested that combining enzymatic allylation of the cap with subsequent labeling in a photoclick reaction was feasible. This could be experimentally validated. Our approach generates a turn-on fluorophore site-specifically at the 5’ cap and therefore presents an important step towards labeling of eukaryotic mRNAs in a bioorthogonal manner. 相似文献