Appl. Syst. Innov., Volume 2, Issue 3 (September 2019) – 12 articles

Internet-of-Things (IoT) is an enabling technology for numerous initiatives worldwide such as manufacturing, smart cities, precision agriculture, and eHealth. The massive field data aggregation of distributed administered IoT devices allows new insights and actionable information for dynamic intelligent decision-making. In such distributed environments, data integrity, referring to reliability and consistency, is deemed insufficient and requires immediate facilitation. In this article, we introduce a distributed ledger (DLT)-based system for ensuring IoT data integrity which securely processes the aggregated field data. Its uniqueness lies in the embedded use of IOTA’s ledger, called “The Tangle”, used to transmit and store the data. Our approach shifts from a cloud-centric IoT system, where the Super nodes simply aggregate and push data to the cloud, to a node-centric system, where each Super node owns the data pushed in a distributed and decentralized database (i.e., the Tangle). The backend serves as a consumer of data and a provider of additional resources, such as administration panel, analytics, data marketplace, etc. The proposed implementation is highly modularand constitutes a significant contribution to the Open Source communities, regarding blockchain and IoT. Full article

Due to extreme environmental loadings and aging conditions, maintaining structural integrity for offshore structures is critical to their safety. Non-destructive testing of risers plays a key role in identifying defects developing within the structure, allowing repair in a timely manner to mitigate against failures which cause damage to the environment and pose a hazard to human operators. However, in order to be cost effective the inspection must be carried out in situ, and this poses significant safety risks if undertaken manually. Therefore, enabled by advancements in automation and communication technologies, efforts are being made to deploy inspection systems using robotic platforms. This paper proposes a distributed networked communication system to meet the control requirements of a precision rotary scanner for inspection of underwater structures aimed at providing a robotic inspection system for structural integrity in an offshore environment. The system is configured around local control units, a fieldbus network, and a supervisory control system accounting for the environment conditions to provide enhanced control of actuators for automated inspection of offshore structures. Full article

Performance testing of components and subsystems of buildings is a promising practice for increasing energy efficiency and closing gaps between intended and actual performance of buildings. A typical shortcoming of performance testing is the difficulty of linking a failing test to a faulty or underperforming component. Furthermore, a failing test can also be linked to a wrongly configured performance test. In this paper, we present Building Metadata Performance Testing (BuMPeT), a method that addresses this shortcoming by using building metadata models to extend performance testing with fault detection and diagnostics (FDD) capabilities. We present four different procedures that apply BuMPeT to different data sources and components. We have applied the proposed method to a case study building, located in Denmark, to test its capacity and benefits. Additionally, we use two real case scenarios to showcase examples of failing performance tests in the building, as well as discovery of causes of underperformance. Finally, to examine the limits to the benefits of the applied procedure, a detailed elaboration of a hypothetical scenario is presented. Our findings demonstrate that the method has potential and it can serve to increase the energy efficiency of a wide range of buildings. Full article

The modern cellular technologies are expected to provide high data rates and massive connectivity in fifth generation (5G) systems; however, this may be impossible through traditional radio access techniques. Recently, non-orthogonal multiple access (NOMA) has emerged as one of the promising cellular techniques for modern cellular communications with its ability to provide access for multiple users to the network over the same system resources. This paper studies resource management problem for downlink transmission of multiuser NOMA system. Our objective is to optimize both frequency and power resources for sum capacity maximization while taking into account each user minimum capacity requirement. Firstly, the problem of resource management decouples into two subproblems, that is, efficient sub-channel assignment and optimal power allocation, respectively. Secondly, for given power at base station, we design two sub-optimal algorithms for sub-channel assignment based on user channel condition and user minimum capacity requirement, respectively. Lastly, for any given sub-channel assignment, the problem first transforms into standard convex optimization problem and then we employ duality theory. To evaluate our proposed NOMA scheme, the enhanced version of existing NOMA optimization scheme is also presented as a benchmark. Results demonstrate that the proposed NOMA resource management scheme outperforms the benchmark NOMA optimization scheme in terms of sum capacity. Full article

The ordered fuzzy number (OFN) is determined as an ordered pair of fuzzy number (FN) and its orientation. FN is widely interpreted as imprecise number approximating real number. We interpret any OFN as an imprecise number equipped with additional information about the location of the approximated number. This additional information is given as orientation of OFN. The main goal of this paper is to determine the relation “greater than or equal to” on the space of all OFNs. This relation is unambiguously defined as an extension of analogous relations on the space of all FN. All properties of the introduced relation are investigated on the basis of the revised OFNs’ theory. It is shown here that this relation is a fuzzy one. The relations “greater than” and “equal to” also are considered. It is proven that the introduced relations are independent on the orientation of the compared OFNs. This result makes it easier to solve optimization tasks using OFNs. Full article

The issue of unintentional islanding in grid interconnection still remains a challenge in grid-connected, Distributed Generation System (DGS). This study discusses the general overview of popular islanding detection methods. Because of the various Distributed Generation (DG) types, their sizes connected to the distribution networks, and, due to the concern associated with out-of-phase reclosing, anti-islanding continues to be an issue, where no clear solution exists. The passive islanding detection technique is the simplest method to detect the islanding condition which compares the existing parameters of the system having some threshold values. This study first presents an auto-ground approach, which is based on the application of three-phase, short-circuit to the islanded distribution system just to reclose and re-energize the system. After that, the data mining-decision tree algorithm is implemented on a typical distribution system with multiple DGs. The results from both of the techniques have been accomplished and verified by determining the Non-Detection Zone (NDZ), which satisfies the IEEE standards of 2 s execution time. From the analysis, it is concluded that the decision tree approach is effective and highly accurate to detect the islanding state in DGs. These simulations in detail compare the old and new methods, clearly highlighting the progress in the field of islanding detection. Full article

This research proposes and investigates an equation for productivity in hybrid workflows regarding its robustness towards the definition of workflows as a hybrid probabilistic systems. The proposed equation and its derivations were formulated through a theoretical framework about information theory, probabilities and complex adaptive systems. By defining a productivity equation for organism-machine-environment interactions, discrete and continuous variables that constitute the systems can be controlled by a mathematical framework where prediction and monitoring aspects of optimization are possible without the limitation of strict empirical methods. Full article

In the past decades, a number of methodologies have been proposed to innovate and improve business processes that play an important role in enhancing the operational efficiency of an organisation in order to attain business competitiveness. Traditional business process modelling (BPM) approaches are process-centric and focus on the workflow, ignoring the data modelling aspects that are essential for today’s data-centric landscape of modern businesses. Hence, a majority of BPM initiatives have failed in several organisations due to the lack of data-driven insights into their business performance. On the other hand, the information systems of today focus more on dataflows using object-oriented modelling (OOM) approaches. Even standard OOM approaches, such as unified modelling language (UML) methods, exhibit inherent weaknesses due to their lack of formalized innovation with business objects and the dynamic control-flows of complex business processes. In addition to these issues, both BPM and OOM approaches have been augmented with an array of complex software tools and techniques which have confused businesses. There is a lack of a common generalized framework that integrates the well-formalised control-flow based BPM approach and the dataflow based OOM approach that is suitable for today’s enterprise systems in order to support organisations to achieve successful business process improvements. This paper takes a modest step to fill this gap. We propose a framework using a structured six-step business process modelling (BPM) guideline combined with a business object-oriented methodology (BOOM) in a unique and practical way that could be adopted for improving an organisation’s process efficiency and business performance in contemporary enterprise systems. Our proposed business object-oriented process modelling (BOOPM) framework is applied to a business case study in order to demonstrate the practical implementation and process efficiency improvements that can be achieved in enterprise systems using such a structured and integrated approach. Full article

In this paper, the performance of nanofluids in a Parabolic Trough Concentrating Solar Collector (CSP)-based power generation plant, an Organic Rankine Cycle (ORC), and a Thermal Energy Storage (TES) system is studied. This study is intended to investigate the enhancement effect and characteristics of nanofluids Al₂O₃, CuO, Fe₃O₄ and SiO₂ in integrated concentrating solar power (CSP) with ORC, and TES under different solar radiations, angles of incidence, and different nanofluid concentrations. The refrigerant mixture used in the ORC loop to enhance the ORC efficiency is an environmentally sound quaternary mixture composed of R134a, R245fa, R125, R236fa. The results showed that the power absorbed, and power collected by the CSP collector and thermal energy stored in the storage tank are enhanced with the increase of the solar radiation. It was also found that the CSP hybrid system efficiency has been enhanced mainly by the increase of the solar radiation and higher nanofluid concentrations over the thermal oil as base fluid. Also, the study concludes that the nanofluid CuO outperforms the other nanofluids—Al₂O₃, Fe₃O₄ and SiO₂—and has the highest CSP solar collector performance compared to the other nanofluids and thermal oil base fluid under study at similar conditions. Finally, it was found that the model’s prediction compares fairly with data reported in the literature; however, some discrepancies exist between the model’s prediction and the experimental data. Full article

The estimation of the average daily, monthly and annual direct normal solar irradiation (DNI) was done in the region hosting the Mario Zucchelli Station, in the bay of Terra Nova (Antarctica). Estimates are based on measurements of direct normal (DNI), horizontal global (GHI) and horizontal diffuse (Diff.HI) irradiations, observed by a solar-metric acquisition station installed during the XXVIII scientific expedition carried out in the austral summer 2012/2013 as part of the National Plan of Research in Antarctica (PNRA). The contemporary observations of all three irradiations allowed the setting up of the model for the estimation of the DNI starting from the values of the GHI only, validated for the weather conditions of the Antarctic region. Subsequently, the long-time data reconstruction of the DNI values thanks to the availability of several years' hourly measurements of GHI at the Mario Zucchelli base has been carried out using the meteorological acquisition data installed both at the base and in places scattered around it. The final results make feasible the estimation of solar potential for concentrated solar technology according to long measurements of GHI. Overall, we propose a clean technology based on a renewable power plant and a specific example with a tendency toward a decreased human carbon footprint in the atmosphere of this protected area. Full article

In engineering design, optimization methods are frequently used to improve the initial design of a product. However, the selection of an appropriate method is challenging since many methods exist, especially for the case of simulation-based optimization. This paper proposes a systematic procedure to support this selection process. Building upon quality function deployment, end-user and design use case requirements can be systematically taken into account via a decision matrix. The design and construction of the decision matrix are explained in detail. The proposed procedure is validated by two engineering optimization problems arising within the design of box-type boom cranes. For each problem, the problem statement and the respectively applied optimization methods are explained in detail. The results obtained by optimization validate the use of optimization approaches within the design process. The application of the decision matrix shows the successful incorporation of customer requirements to the algorithm selection. Full article

This study aims to simulate the use of renewable energy in the form of different energy sources, such as solar cells, district heating, and in the presence of battery storage and for high penetration of electric vehicles in a typical Swedish power grid. The EnergyPLAN software is used. The purpose is to examine the demands in order to cope with the needs that may arise and to create a better understanding of how renewable energy affects the power balance and future investments in the case of a typical Swedish distribution system. The importance of this research is mainly based on the fact that it represents a real network, as it operates today, which is analyzed using the expected electric vehicle penetration. The aim is to investigate the expansion needs for maintaining the current quality for service despite the addition of new loads. In addition, the regional and national special regulatory and operational requirements are taken into account and described in this work. Full article