Septimiu Nechifor

Design and Implementation of a Service-Oriented Architecture for the Optimization of Industrial Applications

A novel architecture for the field of industrial automation is described, the goals of which are: 1) computation of optimal production plans; 2) automated usage of the optimized plans; 3) flexibility and reusability at development and maintenance; and 4) seamless transition from current practice to the approach introduced herein. The architecture consists of three main components: 1) a set of OPC unified architecture (UA) servers, which are used to model the information from the device level; 2) a set of services organized into two layers (basic and complex services), which act as a link between the first and the third layer; and 3) a constraint satisfaction problem (CSP) layer for the computation of production plans. Extensive performance tests motivate the choice of the service development framework, and prove the effectiveness of the special adapter software solution for the integration of current devices and the ability of the UA server to manage a high number of UA connections. As a proof-of-concept, the architecture has been tested for a real manufacturing problem composed of four flexible manufacturing systems. The results show that the architecture is able to efficiently control and monitor a real manufacturing process according to an optimized schedule with over 99% of the time spent on the manufacturing.

Efficient address space generation for an OPC UA server

The new OPC Unified Architecture has been introduced as a replacement for the existing COM‐based specifications. The article describes a generalized algorithm for the automatic generation of the address space structure for an UA server. First, we present the general startup procedure of an OPC UA server, focusing on the address space generation step. Afterwards we introduce specialized algorithms for the generation of the type nodes, of object, variable, method and view nodes. Finally the additional references are added to the fully meshed address space. The basic ideas of the algorithms are: the splitting of the nodes into groups and the sequential addition of the groups to the address space, and the naming of a main reference for every target node. The algorithms have been applied for an aggregating UA server which models the devices of an assembly line. The main advantages are: shorter development time, easier maintenance and the possibility to add nodes to the address space in both online and offline mode. Copyright

Autonomic monitoring approach based on CEP and ML for logistic of sensitive goods

The main objective of this work is to develop a framework for supporting the development of applications for logistic companies that transport perishable goods (food and medicines). Reducing the amount of lost and damaged perishable goods during transportation and storage represents a substantial global challenge, which imply the implementation of cold chain monitoring at all levels of the supply chains. The framework contains several components that enable: (1) the real-time monitoring of goods during transportation; (2) forecast the temperatures of parcels; (3) generate real-time alerts/early warning when the product are not stored according to the acceptance criteria.

Using Complex Event Processing for implementing a geofencing service

Geofencing is one of the components in the wider spectra of Ambient Assisted Living related applications. Such applications are meant to provide support to persons with disabilities or to those impaired, as well as to their caretakers. Within this context, geofencing targets the safe mobility of such persons. As mobility related data can be translated into events with a temporal dimension, we have developed a geofencing service based on the Complex Event Processing paradigm. This decision was supported also by the fact that Ambient Assisted Living applications, in general, are often considered for integration into event rich environments, such as those resulting from smart cities infrastructure. The ability of Complex Event Processing to handle vast amounts of time correlated events from multiple sources meets the requirements imposed by the geofencing service. This paper presents the architecture of a Complex Event Processing based geofencing service along with the results obtained during the evaluation phase of the first prototype.

Predictive analytics based on CEP for logistic of sensitive goods

Reducing the amount of lost and damaged perishable goods (food and medicines) during transportation and storage represents a substantial global challenge, which imply the implementation of cold chain monitoring at all levels of the supply chains. The main objective of this work is to develop an IoT enabled infrastructure, which supports the development of smart transportation specific applications. The proposed infrastructure contains an emulator, which can be used for emulating the conditions inside a truck during the transportation process and some CEP based tools for processing the data generated by the sensors.

Real-time scheduling of mobile agents using answer set programming

Scheduling is required in a multitude of domains: public transportation, logistics, delivery of goods, events, component delivery for production plants or in the case of assembly lines. Most of the times, the scheduled activities are performed by agents, either humans or autonomous systems, operating in complex environments subject to change during the agents operation. Usually these changes in the environment have an impact on the initial data based upon which the scheduling was performed thus requiring new working configurations to be generated for the agents. This paper presents the solving of a scheduling problem which extends the traveling salesman scenario through the use of ASP (Answer Set Programming). The method was integrated and tested in the CoReMo simulator whose goal is to provide a platform for the development and evaluation of novel algorithms dealing with event-driven configuration systems.

A public transportation journey planner enabled by IoT data analytics

Using the CityPulse framework we developed a proof of concept application for Braşov public transportation company. The application provides route recommendations and incident notifications for the citizens who travel by bus. This is achieved by processing in real-time the data streams about bus arrivals in stations and the incidents reported by citizens. The proof of concept application was presented to the representatives of Braşov municipality and public transport company.

How to Manage and Search/Retrieve Information Objects

We present the overall vision for a network of information, illustrating the fundamental ideas, and explaining the mechanisms currently under development that will bring about a major paradigm change in networking. After briefly reviewing relevant scenarios where the current host-centric approach to information storage and retrieval is ill-suited for, we introduce how a new networking paradigm emerges, by adopting the information-centric network architecture approach. We illustrate how information retrieval may look like in the future, emphasizing on the user perspective. We then put forward the architectural requirements for a network of information. A description of the mechanisms, the “nuts and bolts” so to speak, of the technologies that implement a network of information is provided. We describe a network of information operation, providing examples and highlighting performance improvement. A long-term view is taken, with a discussion on evolution.

Fault recovery mechanism for smart city environments

In this paper we present the work done to develop a fault recovery component for the situation when the quality of the data streams from a smart city environment drops. The fault recovery component is able to generate estimated values when the stream generates invalid or missing observations. The component is easy to configure and deploy for a large number of data streams from a smart city environment. As a result of that, the fault recovery component contains an incremental learning model, which is able to train itself during component execution. The paper describes the architecture of the fault recovery component and the result of the evaluation done for three candidate incremental learning models.

Event Detection for Urban Dynamic Data Streams

This paper presents a framework for processing the data generated by Smart City sensors and IoT data streams in real-time. The scope of processing is to detect various event patterns from the raw data. The framework is extensible because at any moment new data sources can be registered or new specific event detection mechanism can be deployed. The framework offers a HTTP interface which can be used to provide details about each data stream. In order to connect to the heterogeneous data source end points and fetching the observations a concept of simple adaptable data wrappers is introduced. Having the streams registered into the framework, the domain expert can deploy (using a Java API) the event detection mechanism. The domain expert (maybe with some help from an application developer) has only to develop the data wrappers and event detection modules. Once the modules are developed, they can be deployed any time and on any numbers for different sensors of the same type, respective similar events to be detected.