TY  - JOUR
A1  - Lesch, Veronika
A1  - König, Maximilian
A1  - Kounev, Samuel
A1  - Stein, Anthony
A1  - Krupitzer, Christian
T1  - Tackling the rich vehicle routing problem with nature-inspired algorithms
JF  - Applied Intelligence
N2  - In the last decades, the classical Vehicle Routing Problem (VRP), i.e., assigning a set of orders to vehicles and planning their routes has been intensively researched. As only the assignment of order to vehicles and their routes is already an NP-complete problem, the application of these algorithms in practice often fails to take into account the constraints and restrictions that apply in real-world applications, the so called rich VRP (rVRP) and are limited to single aspects. In this work, we incorporate the main relevant real-world constraints and requirements. We propose a two-stage strategy and a Timeline algorithm for time windows and pause times, and apply a Genetic Algorithm (GA) and Ant Colony Optimization (ACO) individually to the problem to find optimal solutions. Our evaluation of eight different problem instances against four state-of-the-art algorithms shows that our approach handles all given constraints in a reasonable time.
KW  - logistics
KW  - rich vehicle routing problem
KW  - ant-colony optimization
KW  - genetic algorithm
KW  - real-world application
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-268942
SN  - 1573-7497
VL  - 52
ER  - 
TY  - JOUR
A1  - Prantl, Thomas
A1  - Zeck, Timo
A1  - Bauer, Andre
A1  - Ten, Peter
A1  - Prantl, Dominik
A1  - Yahya, Ala Eddine Ben
A1  - Ifflaender, Lukas
A1  - Dmitrienko, Alexandra
A1  - Krupitzer, Christian
A1  - Kounev, Samuel
T1  - A Survey on Secure Group Communication Schemes With Focus on IoT Communication
JF  - IEEE Access
N2  - A key feature for Internet of Things (IoT) is to control what content is available to each user. To handle this access management, encryption schemes can be used. Due to the diverse usage of encryption schemes, there are various realizations of 1-to-1, 1-to-n, and n-to-n schemes in the literature. This multitude of encryption methods with a wide variety of properties presents developers with the challenge of selecting the optimal method for a particular use case, which is further complicated by the fact that there is no overview of existing encryption schemes. To fill this gap, we envision a cryptography encyclopedia providing such an overview of existing encryption schemes. In this survey paper, we take a first step towards such an encyclopedia by creating a sub-encyclopedia for secure group communication (SGC) schemes, which belong to the n-to-n category. We extensively surveyed the state-of-the-art and classified 47 different schemes. More precisely, we provide (i) a comprehensive overview of the relevant security features, (ii) a set of relevant performance metrics, (iii) a classification for secure group communication schemes, and (iv) workflow descriptions of the 47 schemes. Moreover, we perform a detailed performance and security evaluation of the 47 secure group communication schemes. Based on this evaluation, we create a guideline for the selection of secure group communication schemes.
KW  - Internet of Things
KW  - encryption
KW  - secure group communication
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300257
VL  - 10
SP  - 99944
EP  - 99962
ER  -