Residual Inter-Contact Time for Opportunistic Networks with Pareto Inter-Contact Time: Two Nodes Case

PDPTA'15 : The 21st International Conference on Parallel and Distributed Processing Techniques and Applications , Jul 27-30, 2015 , Las Vegas, NV, USAOpportunistic networks (OppNets) are appealing for many applications, such as wild life monitoring, disaster relief and mobile data offloading. In such a network, a message arriving at a mobile node could be transmitted to another mobile node when they opportunistically move into each other's transmission range (called in contact), and after multi-hop similar transmissions the message will finally reach its destination. Therefore, for one message the time interval from its arrival at a mobile node to the time the mobile node contacts another node constitutes an essential part of the message's whole delay. Thus, studying stochastic properties of this time interval between two nodes lays a solid foundation for evaluating the whole message delay in OppNets. Note that this time interval is within the time interval between two consecutive node contacts (called inter-contact time) and it is also referred to as residual inter-contact time. In this paper, we derive the closed-form distribution for residual inter-contact time. First, we formulate the contact process of a pair of mobile nodes as a renewal process, where the inter-contact time features the popular Pareto distribution. Then, we derive, based on the renewal theory, closed-form results for the transient distribution of residual inter-contact time and also its limiting distribution. Our theoretical results on distribution of residual inter-contact time are validated by simulations

Relational Algebra for In-Database Process Mining

The execution logs that are used for process mining in practice are often obtained by querying an operational database and storing the result in a flat file. Consequently, the data processing power of the database system cannot be used anymore for this information, leading to constrained flexibility in the definition of mining patterns and limited execution performance in mining large logs. Enabling process mining directly on a database - instead of via intermediate storage in a flat file - therefore provides additional flexibility and efficiency. To help facilitate this ideal of in-database process mining, this paper formally defines a database operator that extracts the 'directly follows' relation from an operational database. This operator can both be used to do in-database process mining and to flexibly evaluate process mining related queries, such as: "which employee most frequently changes the 'amount' attribute of a case from one task to the next". We define the operator using the well-known relational algebra that forms the formal underpinning of relational databases. We formally prove equivalence properties of the operator that are useful for query optimization and present time-complexity properties of the operator. By doing so this paper formally defines the necessary relational algebraic elements of a 'directly follows' operator, which are required for implementation of such an operator in a DBMS

Measuring the phonon-assisted spectral function by using a non-quilibrium three-terminal single-molecular device

The electron transport through a three-terminal single-molecular transistor (SMT) is theoretically studied. We find that the differential conductance of the third and weakly coupled terminal versus its voltage matches well with the spectral function versus the energy when certain conditions are met. Particularly, this excellent matching is maintained even for complicated structure of the phonon-assisted side peaks. Thus, this device offers an experimental approach to explore the shape of the phonon-assisted spectral function in detail. In addition we discuss the conditions of a perfect matching. The results show that at low temperatures the matching survives regardless of the bias and the energy levels of the SMT. However, at high temperatures, the matching is destroyed.Comment: 9 pages, 5 figure

Source Delay in Mobile Ad Hoc Networks

Source delay, the time a packet experiences in its source node, serves as a fundamental quantity for delay performance analysis in networks. However, the source delay performance in highly dynamic mobile ad hoc networks (MANETs) is still largely unknown by now. This paper studies the source delay in MANETs based on a general packet dispatching scheme with dispatch limit $f$ (PD-$f$ for short), where a same packet will be dispatched out up to $f$ times by its source node such that packet dispatching process can be flexibly controlled through a proper setting of $f$. We first apply the Quasi-Birth-and-Death (QBD) theory to develop a theoretical framework to capture the complex packet dispatching process in PD-$f$ MANETs. With the help of the theoretical framework, we then derive the cumulative distribution function as well as mean and variance of the source delay in such networks. Finally, extensive simulation and theoretical results are provided to validate our source delay analysis and illustrate how source delay in MANETs are related to network parameters.Comment: 11page

Machine Learning on generalized Complete Intersection Calabi-Yau Manifolds

Generalized Complete Intersection Calabi-Yau Manifold (gCICY) is a new construction of Calabi-Yau manifolds established recently. However, the generation of new gCICYs using standard algebraic method is very laborious. Due to this complexity, the number of gCICYs and their classification still remain unknown. In this paper, we try to make some progress in this direction using neural network. The results showed that our trained models can have a high precision on the existing type $(1,1)$ and type $(2,1)$ gCICYs in the literature. Moreover, They can achieve a $97\%$ precision in predicting new gCICY which is generated differently from those used for training and testing. This shows that machine learning could be an effective method to classify and generate new gCICY.Comment: 20 pages, 4 figure

Quantitative Analysis of Chromosome/Gene Spatial Distribution

Zusammenfassung Die Fortschritte in den Bereichen Zellbildgebung und Mikroskopie haben eine intensive Untersuchung der räumlichen Anordnung von Chromosomen bzw. Genen im Verlauf der letzten Jahre möglich gemacht. Es wurden bereits Algorithmen zur Quantifizierung der räumlichen Anordnung von Chromosomen bzw. Genen entwickelt, wobei die meisten dieser Methoden jedoch auf zweidimensionalen (2D) Bilddaten basieren. Um dreidimensionale (3D) konfokale Bilddaten verarbeiten zu können, ist es notwendig neue Algorithmen zu entwickeln, die auf 3D Datensätzen basieren. In dieser Arbeit werden neue Methoden zur Beschreibung, Analyse und Visualisierung der 3D Verteilung von Chromosomen und Genen in fixierten Zellkernen in 3D Bilddaten präsentiert, die basierend auf Konzepten der objektorientierten Programmierung in der Programmiersprache Java implementiert wurden. Kapitel 2 beschreibt verschiedene Softwarewerkzeuge zur Bestimmung von Ähnlichkeiten der Anordnung von Chromosomen unter Verwendung der Krümmungsenergie von Thin-plate Splines sowie zur Berechnung von geometrischen Mittelpunkten, Distanzen und Winkeln. Zwei anwendungsorientierte Projekte zur räumlichen Verteilung von Chromosomen bzw. Genen werden in Kapitel 3 bzw. Kapitel 4 vorgestellt. Die Vorteile, Grenzen und weitere Verbesserungen von diesen Computermethoden werden ausführlich in Kapitel 5 behandelt. Danach wird ein neues Modell der Vererbung der räumlichen Chromosomenordnung erläutert. Die quantitative Analyse in Kapitel 3 zeigt, dass die Unterschiede in der Anordnung von Chromosomenterritorien kontinuierlich mit der Anzahl der Zellgenerationen (d.h. Zellteilungen) zunehmen. In HeLa Zellklonen sind die Unähnlichkeiten in der Anordnung von Chromosomenterritorien nach fünf oder sechs Zellteilungen bereits so groß wie die zwischen unverwandten, zufällig ausgewählten Zellen. Die quantitative Analyse in Kapitel 4 zeigt, dass während der Interphase die Positionen der untersuchten Gene (MLL und fünf seiner Translokationspartner) sowie von vier chromosomalen Kontroll-Loci ein charakteristisches Verteilungsmuster innerhalb des Zellkerns besitzen. Dies gilt für jede der untersuchten hämatopoietischen Zellen. Die in dieser Arbeit präsentierten Methoden zur Bestimmung der Ähnlichkeit der Anordnung von Chromosomen unter Verwendung von punktbasierter Registrierung liefern zum ersten Mal Beispiele zur Analyse und Bewertung der Vererbung einer räumlichen Verteilung von Chromosomen über mehrere Zellteilungen hinweg. Gleichzeitig wird zum ersten Mal die räumliche Verteilung von Genen, vor allem des Genes MLL und einiger Translokationspartner, im 3D Raum des Interphasezellkerns hämatopoietischer Zellen quantitativ beschrieben

An Endorsement-Based Mobile Payment System for a Disaster Area

AINA-2015 : IEEE 29th International Conference on Advanced Information Networking and Applications , Mar 24-27, 2015 , Gwangju, KoreaA payment system in a disaster area is essential for people to buy necessities such as groceries, clothing, and medical supplies. However, existing payment systems require the needed communication infrastructures (like wired networks and cellular networks) to enable transactions, so that these systems cannot be relied on in disaster areas, where these communication infrastructures may be destroyed. In this paper, we propose a mobile payment system, adopting infrastructure less mobile adhoc networks (MANETs), which allow users to shop in disaster areas while providing secure transactions. Specifically, we propose an endorsement-based scheme to guarantee each transaction and a scheme to provide monitoring based on location information, and thus achieve transaction validity and reliability. Our mobile payment system can also prevent collusion between two parties and reset and recover attacks by any user. Security is ensured by using location-based mutual monitoring by nearby users, avoiding thereby double spending in the system