Manual of individual water supply systems. Developed in cooperation with the Joint Committee on Rural Sanitation.

"Revision of PHS Publication no. 24, Individual water supply systems [by the Joint Committee on Rural Sanitation] issued in 1950."

A distributed systems approach to secure Internet mail

One of the obstacles to improved security of the Internet is ad hoc development of technologies with different design goals and different security goals. This paper proposes reconceptualizing the Internet as a secure distributed system, focusing specifically on the application layer. The notion is to redesign specific functionality, based on principles discovered in research on distributed systems in the decades since the initial development of the Internet. Because of the problems in retrofitting new technology across millions of clients and servers, any options with prospects of success must support backward compatibility. This paper outlines a possible new architecture for internet-based mail which would replace existing protocols by a more secure framework. To maintain backward compatibility, initial implementation could offer a web browser-based front end but the longer-term approach would be to implement the system using appropriate models of replication. (C) 2005 Elsevier Ltd. All rights reserved.

A study of adaptive load balancing algorithms for distributed systems

With the advent of distributed computer systems with a largely transparent user interface, new questions have arisen regarding the management of such an environment by an operating system. One fertile area of research is that of load balancing, which attempts to improve system performance by redistributing the workload submitted to the system by the users. Early work in this field concentrated on static placement of computational objects to improve performance, given prior knowledge of process behaviour. More recently this has evolved into studying dynamic load balancing with process migration, thus allowing the system to adapt to varying loads. In this thesis, we describe a simulated system which facilitates experimentation with various load balancing algorithms. The system runs under UNIX and provides functions for user processes to communicate through software ports; processes reside on simulated homogeneous processors, connected by a user-specified topology, and a mechanism is included to allow migration of a process from one processor to another. We present the results of a study of adaptive load balancing algorithms, conducted using the aforementioned simulated system, under varying conditions; these results show the relative merits of different approaches to the load balancing problem, and we analyse the trade-offs between them. Following from this study, we present further novel modifications to suggested algorithms, and show their effects on system performance.

The relative performance of scalable load balancing algorithms in loosely-coupled distributed systems. Available in 2 volumes.

The computer systems of today are characterised by data and program control that are distributed functionally and geographically across a network. A major issue of concern in this environment is the operating system activity of resource management for different processors in the network. To ensure equity in load distribution and improved system performance, load balancing is often undertaken. The research conducted in this field so far, has been primarily concerned with a small set of algorithms operating on tightly-coupled distributed systems. More recent studies have investigated the performance of such algorithms in loosely-coupled architectures but using a small set of processors. This thesis describes a simulation model developed to study the behaviour and general performance characteristics of a range of dynamic load balancing algorithms. Further, the scalability of these algorithms are discussed and a range of regionalised load balancing algorithms developed. In particular, we examine the impact of network diameter and delay on the performance of such algorithms across a range of system workloads. The results produced seem to suggest that the performance of simple dynamic policies are scalable but lack the load stability of more complex global average algorithms.

Agent-based Anomalies Monitoring in Distributed Systems

In this paper an agent-based approach for anomalies monitoring in distributed systems such as computer networks, or Grid systems is proposed. This approach envisages on-line and off-line monitoring in order to analyze users’ activity. On-line monitoring is carried in real time, and is used to predict user actions. Off-line monitoring is done after the user has ended his work, and is based on the analysis of statistical information obtained during user’s work. In both cases neural networks are used in order to predict user actions and to distinguish normal and anomalous user behavior.

Intelligent Model of User Behavior in Distributed Systems

We present a complex neural network model of user behavior in distributed systems. The model reflects both dynamical and statistical features of user behavior and consists of three components: on-line and off-line models and change detection module. On-line model reflects dynamical features by predicting user actions on the basis of previous ones. Off-line model is based on the analysis of statistical parameters of user behavior. In both cases neural networks are used to reveal uncharacteristic activity of users. Change detection module is intended for trends analysis in user behavior. The efficiency of complex model is verified on real data of users of Space Research Institute of NASU-NSAU.

Добавена реалност (Augmented Reality) – същност и приложение

Доклад, поместен в сборника на Националната конференция "Образованието в информационното общество", Пловдив, май, 2012 г.

Augmented Reality as a Method for Expanded Presentation of Objects of Digitized Heritage

Augmented reality is the latest among information technologies in modern electronics industry. The essence is in the addition of advanced computer graphics in real and/or digitized images. This paper gives a brief analysis of the concept and the approaches to implementing augmented reality for an expanded presentation of a digitized object of national cultural and/or scientific heritage. ACM Computing Classification System (1998): H.5.1, H.5.3, I.3.7.

Temporal Mining for Distributed Systems

Many systems and applications are continuously producing events. These events are used to record the status of the system and trace the behaviors of the systems. By examining these events, system administrators can check the potential problems of these systems. If the temporal dynamics of the systems are further investigated, the underlying patterns can be discovered. The uncovered knowledge can be leveraged to predict the future system behaviors or to mitigate the potential risks of the systems. Moreover, the system administrators can utilize the temporal patterns to set up event management rules to make the system more intelligent. With the popularity of data mining techniques in recent years, these events grad- ually become more and more useful. Despite the recent advances of the data mining techniques, the application to system event mining is still in a rudimentary stage. Most of works are still focusing on episodes mining or frequent pattern discovering. These methods are unable to provide a brief yet comprehensible summary to reveal the valuable information from the high level perspective. Moreover, these methods provide little actionable knowledge to help the system administrators to better man- age the systems. To better make use of the recorded events, more practical techniques are required. From the perspective of data mining, three correlated directions are considered to be helpful for system management: (1) Provide concise yet comprehensive summaries about the running status of the systems; (2) Make the systems more intelligence and autonomous; (3) Effectively detect the abnormal behaviors of the systems. Due to the richness of the event logs, all these directions can be solved in the data-driven manner. And in this way, the robustness of the systems can be enhanced and the goal of autonomous management can be approached. This dissertation mainly focuses on the foregoing directions that leverage tem- poral mining techniques to facilitate system management. More specifically, three concrete topics will be discussed, including event, resource demand prediction, and streaming anomaly detection. Besides the theoretic contributions, the experimental evaluation will also be presented to demonstrate the effectiveness and efficacy of the corresponding solutions.

AR-park för Android : Augmented Reality park i Sundsvall

Målet med detta projekt är att ta fram en applikationsprototyp för Androidenheter som ska locka användare av applikationen till och tillbaka till broparken i Skönsberg med hjälp av augmented-reality. Applikationen ska känna av om användaren befinner sig inom eller utanför parkens område och visa olika bilder/modeller på specifika GPS-koordinater i det digitala lagret beroende på användarens positionering. Arbetet har genomförts i samarbete med Dohi på uppdrag av Sundsvalls kommun där regelbundna möten hafts med uppdragsgivaren. Utvecklingen av applikationen sker i PhoneGap med Wikitude-plugin. Projektet har resulterat i en applikationsprototyp som använder ActionRanges, som är en typ av GeoFence, för att presentera olika bilder hämtade från en egen server i det digitala lagret beroende på användarens position. Användarna har inom parkens område möjlighet att själv påverka de bilder som visas i det digitala lagret genom att i applikationen ta en bild som laddas upp till servern där bilderna lagras och där bilden som tagits även visar det digitala lagret.

Entwicklung eines Funktionsumfangs für Augmented Reality Führungen in Hochschulbibliotheken

Anwendungen in Bibliotheken auf Basis von Augmented Reality (AR), der Erweiterung der Realität durch zusätzliche, virtuelle Informationen, existieren bislang nur vereinzelt. Das vom Bundesministerium für Wirtschaft und Energie geförderte Forschungsprojekt mylibrARy ermittelt seit Juni 2014 Szenarien für den Einsatz von AR in Bibliotheken und Informationseinrichtungen. Das Projekt zielt auf die Entwicklung einer deutschlandweit einsetzbaren Applikation (App). An diesen Gedanken knüpft die vorliegende Arbeit mit der Entwicklung eines Konzepts für Einführungen in Hochschulbibliotheken mittels AR-Technik. Aus der Analyse aktueller Führungsmodelle von Bibliotheken der Hochschulen im Exzellenzcluster 2012-2017, werden die für die Modellführung benötigten charakteristischen Merkmale einer Bibliotheksführung abgeleitet. Auf die technisch relevanten Grundlagen der AR folgt eine Bestandsaufnahme der bisherigen Augmented-Reality-Projekte im internationalen Bibliothekskontext. Daran schließt die Formulierung der theoretischen Anforderungen und die Ausarbeitung der Funktionen im Einzelnen. Nachfolgend lenkt eine kritische Betrachtung den Fokus auf Mehrwert und Risiken der AR für Bibliothek und Nutzer. Mit einer Zusammenfassung und dem Ausblick auf die zukünftige Entwicklung findet die Arbeit ihren Abschuss.

Evaluating the use of mobile collaborative augmented reality within field service networks: the case of Océ Italia – Canon Group

The adoption of Augmented Reality (AR) technologies can make the provision of field services to industrial equipment more effective. In these situations, the cost of deploying skilled technicians in geographically dispersed locations must be accurately traded off with the risks of not respecting the service level agreements with the customers. This paper, through the case study of a leading OEM in the production printing industry, presents the challenges that have to be faced in order to favour the adoption of a particular kind of AR named Mobile Collaborative Augmented Reality (MCAR). In particular, this study uses both qualitative and quantitative research. Firstly, a demonstration to show how MCAR can support field service was settled in order to achieve information about the use experience of the people involved. Then, the entire field force of Océ Italia – Canon Group was surveyed in order to investigate quantitatively the technicians’ perceptions about the usefulness and ease of use of MCAR, as well as their intentions to use this technology.