Informatics

A practical comparison of Alloy and Spin
Because potential users have to choose a formal method before they can start using one, research on assessing the applicability of specific formal methods might be as effective in encouraging their use as work on the methods themselves. This comparison of Alloy and Spin is based on a demanding project that exploited the full capabilities of both languages and tools. The study exposed issues not...


Fair ticket pricing in public transport as a constrained cost allocation game
Ticket pricing in public transport usually takes a welfare maximization point of view. Such an approach, however, does not consider fairness in the sense that users of a shared infrastructure should pay for the costs that they generate. We propose an ansatz to determine fair ticket prices that combines concepts from cooperative game theory and linear and integer programming. The ticket pricing ...
Mean-risk analysis of wholesale price contracts with stochastic price-dependent demand
In supply chain management, it is prevalent to design contract for coordination or proper risk-sharing in the supply chain. However, when a supply chain contract is developed based on the concept of expectation (e.g., expected profit), there is uncertainty risk with respect to the contract value which arises from various uncertainties inherent in the supply chain, such as demand uncertainty, pr...


Optimistic semaphores with non-deterministic choice operation for heterogeneous manycore systems
The Nix operating system permits different roles to be assigned to the cores. One of the roles is to be able to run user-space code with no interrupts from the operating system, which is particularly useful for high-performance computing. System calls are especially expensive to a core playing this role. This paper presents a new implementation of optimistic semaphores that avoid performing exp...
How to re-use a one-time pad safely and almost optimally even if P = NP
Assuming an insecure quantum channel, a quantum computer, and an authenticated classical channel, we propose an unconditionally secure scheme for encrypting classical messages under a shared key, where attempts to eavesdrop the ciphertext can be detected. If no eavesdropping is detected, we can securely re-use the entire key for encrypting new messages. If eavesdropping is detected, we must dis...


On a class of (sigma )-stable Poisson–Kingman models and an effective marginalized sampler
We investigate the use of a large class of discrete random probability measures, which is referred to as the class (mathcal {Q}), in the context of Bayesian nonparametric mixture modeling. The class (mathcal {Q}) encompasses both the the two-parameter Poisson–Dirichlet process and the normalized generalized Gamma process, thus allowing us to comparatively study the inferential advantages of t...
Using OpenFlow to provide cut-through switching in MobilityFirst
Mobile devices are expected to become the Internet’s predominant technology. Current protocols such as TCP/IP were not originally designed with mobility as a key consideration, and therefore underperform under challenging mobile and wireless conditions. MobilityFirst, a clean slate architecture proposal, embraces several key concepts centered around secure identifiers that inherently support ...

Efficient IP lookup using hybrid trie-based partitioning of TCAM-based open flow switches
IP forwarding technique in open flow switch can be done by comparing the destination IP address, which is stored in forwarding table with the input IP prefix. Ternary content-addressable memory (TCAM) is one of the popular mechanisms to store and forward IP packet where flow entries are organized in sorted manner. Searching a prefix value in TCAM uses longest prefix match rather than exact matc...
Fault tolerance mechanisms for virtual data center architectures
A virtual data center (VDC) is a combination of interconnected virtual servers hosted on a physical data center that hosts multiple such VDCs. This enables efficient sharing of the data center’s resources while handling dynamic resource requirements of the clients. The SecondNet architecture (Guo et al. in Proceedings of ACMSIGCOMM conference on data communication, Barcelona, pp 63–74, 2009...

Research on multipath limiting antenna array with fixed phase center
As the Compass satellite system is under construction, various applications are emerging. Multipath mitigation is still a critical problem that must be resolved, especially short delay multipath. Research on multipath mitigation is reported and a multipath limiting antenna array including the algorithm is discussed. The carrier phase data of the receiver are subjected to forward–backward spat...
Efficient Workflow Scheduling for Grid Computing Using a Leveled Multi-objective Genetic Algorithm
Task scheduling and resource allocation are important problems in grid computing. The workflow management system receives inter-dependent tasks from the users and allocates each task to an appropriate resource based on user requirements and constraints such as budget and deadline. Thus this system has a significant effect on performance and the efficient use of resources. In general, mapping ta...

An auxiliary gaze point estimation method based on facial normal
Considering the main disadvantage of the existing gaze point estimation methods which restrict user’s head movement and have potential injury on eyes, we propose a gaze point estimation method based on facial normal and binocular vision. Firstly, we calibrate stereo cameras to determine the extrinsic and intrinsic parameters of the cameras; Secondly, face is quickly detected by Viola–Jones ...
Term frequency combined hybrid feature selection method for spam filtering
Feature selection is an important technology on improving the efficiency and accuracy of spam filtering. Among the numerous methods, document frequency-based feature selections ignore the effect of term frequency information, thus always deduce unsatisfactory results. In this paper, a hybrid method (called HBM), which combines the document frequency information and term frequency information is...
Developer initiation and social interactions in OSS: A case study of the Apache Software Foundation
Maintaining a productive and collaborative team of developers is essential to Open Source Software (OSS) success, and hinges upon the trust inherent among the team. Whether a project participant is initiated as a committer is a function of both his technical contributions and also his social interactions with other project participants. One’s online social footprint is arguably easier to asce...
Algorithms for global protein–protein interaction network alignment
Protein–protein interaction creates a complex relation among molecular organs. The pivotal functionalities among cells depend on these interactions. In the light of computational biology (CB), it is possible to retrieve the exact information regarding these relationships. The global alignments among proteins are more important. Toward the development of the PPI network analysis, various metho...