Abstract IoT (Internet of Things) is a new paradigm which provides a set of new services for the next wave of technological innovations. IoT applications are nearly limitless while enabling seamless integration of the cyber-world with the physical world. However, despite the enormous efforts of standardization bodies, alliances, industries, researchers and others, there are still numerous problems to deal with in order to reach the full potential of IoT. These issues should be considered from various aspects such as enabling technologies, applications, business models, social and environmental impacts. In focus of this paper are open issues and challenges considered from the technological perspective. Just for clarification, we put in light different visions that stand behind this paradigm in order to facilitate a better understanding of the IoT's features. Furthermore, this exhaustive survey provides insights into the state-of-the-art of IoT enabling and emerging technologies. The most relevant among them are addressed with some details. The main scope is to deliver a comprehensive overview of open issues and challenges to be tackled by future research. We provide some insights into specific emerging ideas in order to facilitate future research. Also, this paper brings order in the existing literature by classifying contributions according to different research topics.

For interconnected and complex systems, security is paramount for establishing trust in their correctness and design adequacy. Thus, security needs to be assured and a corresponding security assurance case needs to be presented to system stakeholders, security assessors, as well as to system users. However, security is dynamic by its nature and to maintain its acceptable security level, frequent updates might be required. Traditionally, a security assurance case is built from scratch whenever a change occurs, however given the cost of resources needed for such a task, a more effective and less time consuming way of handling updates is needed. Hence, the challenge of security case run-time adaptation is considered in this work. We survey the state of the art in security assurance and security case development to refine the challenge and identify system decomposition as one the enablers for security case run-time adaptation. We propose to apply system decomposition in terms of services and use service choreographies to facilitate security case run-time adaptation. The proposed approach is illustrated on an E-gas example.

Fault location estimation is a very important question in electric power system, in order to isolate the fault as soon as possible, and to recover the system with minimal interruptions. In that way, electric equipment is less stressed, and buyers more satisfied. Electric power lines are exposed to environment and probability of line failure is generally higher than other system element failure. Current electric power systems are equipped with high sampling rate power quality meters that are installed in the places of common coupling with distribution systems or high voltage consumers. Data obtained by these power quality meters, especially the voltage and current harmonics present a valuable information about system behavior, even in the faulty conditions. In this paper fault location and fault resistance is estimated by using a combination of artificial neural networks and voltage and current harmonics measured by power quality meters installed only in important system busbars. Results obtained from the real 110 kV transmission system show that a proposed algorithm can be used successfully in fault location and fault resistance estimation in one part of the electric power system. This paper makes a contribution to the existing body of knowledge by developing and testing a new method whose application represents a natural and a feasible upgrade using the existing measurement and communication equipment.

Synchronization and ranging in internet of things $(IoT)$ networks are challenging due to the narrowband nature of signals used for communication between IoT nodes. Recently, several estimators for range estimation using phase difference of arrival $(PDoA)$ measurements of narrowband signals have been proposed. However, these estimators are based on data models which do not consider the impact of clock-skew on the range estimation. In this paper, clock-skew and range estimation are studied under a unified framework. We derive a novel and precise data model for PDoA measurements which incorporates the unknown clock-skew effects. We then formulate joint estimation of the clock-skew and range as a two-dimensional (2-D) frequency estimation problem of a single complex sinusoid. Furthermore, we propose: (i) a two-way communication protocol for collecting PDoA measurements and (ii) a weighted least squares (WLS) algorithm for joint estimation of clock-skew and range leveraging the shift invariance property of the measurement data. Finally, through numerical experiments, the performance of the proposed protocol and estimator is compared against the Cramér Rao lower bound demonstrating that the proposed estimator is asymptotically efficient.

Multi-, many-core, hybrid processors and parallel programming languages are slowly becoming pervasive in main- stream computing. It is expected that they will affect a large spectrum of systems, from embedded and general-purpose, to high-end computing systems. This architectural change has already challenged programmers to efficiently write an application code that can scale over many cores to utilize its computational power. Moreover, many heterogeneous architectures exist today, hence there was an emergent need for a uniform interface to these architectures. Recently, Khronos Group defined the Open Computing Language (OpenCL) for abstracting the underlying hardware, which enables software developers to write a portable code across different shared-memory architectures. In this paper, we introduce a new parallel implementation of one of the fastest image segmentation algorithms known as Simple Linear Iterative Clustering based on OpenCL. We evaluate the effectiveness of this implementation using only multi-core GPCPU. Our implementation is fully compatible with sequential implementation. When the algorithm is executed sequentially it utilizes only 25% of total computational power of a GPCPU for any image resolution, while its modified algorithm is able to utilize close to 100% for high resolution images. The resulting algorithm is up to 5×faster than its sequential counterpart.

The “golden” channel, in which the newly-discovered Higgs boson decays to four leptons by means of intermediate vector bosons, is important for determining the properties of the Higgs boson and for searching for subtle new physics effects. Different approaches exist for parametrizing the relevant Higgs couplings in this channel; here we relate the use of pseudo-observables to methods based on specifying the most general amplitude or Lagrangian terms for the HVV interactions. We also provide projections for sensitivity in this channel in several novel scenarios, illustrating the use of pseudo-observables, and analyze the role of kinematic distributions and (ratios of) rates in such H → 4ℓ studies.

Relative age effect (RAE) is a worldwide phenomenon described as consequences of age variations between individuals competing in the same cohort. RAE is based on systems that use January 1 as a cut-off date, probably used to attempt to minimize developmental differences between ages and to ensure a more equitable competition. Previously, in artistic gymnastics, a majority of studies on RAE was conducted in gymnasts of national levels. This study analysed RAE both among and between elite female (NF=1268) and male gymnasts (NM=1186) who participated at all Olympic Games held from 1964 to 2016. By using χ2 test, significant difference were found: 1) within frequencies of total sample of male gymnasts born in a certain month (p<0.001); 2) within frequencies of groups of male gymnasts apparatus finalists born in a certain month (p<0.005); 3) within frequencies of groups of male apparatus finalists born in a certain quarter of the year (p<0.005); 4) within frequencies of groups of male apparatus finalists born in a certain half of the year (p<0.005). As far as female gymnasts are concerned, significant differences have not been found within frequencies of any female group born in a certain month, quarter or halves of the year. Regarding differences between genders, no significant differences have been obtained between frequencies of male and female gymnasts born in certain month, quarter and halves of the year. Despite certain differences among and between genders, the general conclusion was that RAE is not present in elite gymnasts of both genders.

In order to make chemical characterization of two Origanum vulgare L. subspecies in Montenegro, the essential oils of five wild growing populations were analyzed. Among 67 oil constituents, in O. vulgare subsp. hirtum dominant one was oxygenated monoterpene carvacrol (74.3%), while in O. vulgare subsp. vulgare prevailed sesquiterpene hydrocarbons: germacrene D (15.4–27.9%) and β-caryophyllene (7.7–14.6%), and among oxygenated monoterpenes: α- terpineol (4.8–17.8%), linalyl acetate (0.5–9.6%), linalool (3.0–8.8%), thymol (0.2–8.3), terpinene 4-ol (1.5–8.3%). Several of the main essential oil constituents appeared to be highly intercorrelated. Strong positive correlations (r > 0.70; P < 0.01) were observed between α-terpineol and linalyl acetate, α-terpineol and thymol, linalyl acetate and thymol, γ-terpenene and carvacrol, (E)-β-ocimene and β-bisabolene, while strong negative correlations (r < −0.70; P < 0.01) were evidenced between γ-terpenene and β-caryophyllene, γ-terpenene and germacrene D, p-cymene and germacrene D. Multivariate analyses allowed the grouping of the populations into three distinct chemotypes. Population P5 (Origanum vulgare subsp. hirtum) was distinguished from O. vulgare subsp. vulgare populations by predominance of carvacrol, while within the typical subspecies the population P1 (Boljevići) separated from P2 (Radovče), P3 (Lipovo) and P4 (Grahovo) by high oil levels of α-terpineol, linalyl-acetate and thymol.

Antiphospholipid syndrome (APS) is a rare disease characterised by venous and/or arterial thrombosis, pregnancy complications and the presence of specific autoantibodies called antiphospholipid antibodies. This review aims to identify existing clinical practice guidelines (CPG) as part of the ERN ReCONNET project, aimed at evaluating existing CPGs or recommendations in rare and complex diseases. Seventeen papers providing important data were identified; however, the literature search highlighted the scarceness of reliable clinical data to develop CPGs. With no formal clinical guidelines in place, diagnosis and treatment of APS is largely based on consensus and expert opinion. Patients’ unmet need refers to the understanding of the disease and its clinical picture and implications, the need of education for patients, family members and healthcare providers, as well as to the development of monitoring pathways involving multiple healthcare providers.

Objective To report the effort of the European Reference Network for Rare and Complex CONnective tissue and musculoskeletal diseases NETwork working group on Ehlers-Danlos syndromes (EDS) and related disorders to assess current available clinical practice guidelines (CPGs) specifically addressed to EDS, in order to identify potential clinician and patient unmet needs. Methods Systematic literature search in PUBMED and EMBASE based on controlled terms (MeSH and Emtree) and keywords of the disease and publication type (CPGs). All the published articles were revised in order to identify existing CPGs on diagnosis, monitoring and treatment of EDS. Results Literature revision detected the absence of papers reporting good quality CPGs to optimise EDS patient care. The current evidence-based literature regarding clinical guidelines for the EDS was limited in size and quality, and there is insufficient research exploring the clinical features and interventions, and clinical decision-making are currently based on theoretical and limited research evidences. Conclusions Many clinician and patient unmet needs have been identified.

Introduction: The objective of this research was to determine whether vesicoureteral reflux(VUR) was associated with evolution to renal scarring (RS) following a febrile urinary tract infection (UTI) in infants. Materials and methods: Our research included 100 infants, ages up to 1 year with a first febrile UTI. The diagnostic was based on results of: laboratory findings, ultrasonography (USG), voiding cystourethrography (VCUG) and initial and control renal scintigraphy (DMSA renal scan) withtechnetium99mTcsuccimer (dimercaptosuccinic acid), to assess the acute pyelonephritis (APN), VUR and RS. Results: APN was proven with DMSA renal scan in 66 (66%) infants. Twenty-two infants (33.3%) had VUR in-group of patients with APN. On the control DMSA scan, performed 6 months after the first DMSA, the presence of RS was found in 18 (27.27%) infants. In infants with renal scars VUR were discovered in 9 of them (50%). Conclusions: The pathogenesis of RS after febrile UTI in young children is multifactorial. Children with VUR have an increased risk for APN and RS. However, VUR is not the only precondition for RS. Creating a renal scarring cannot be imagined without the inflammatory process of the upper urinary system. Therefore, early detection and treatment of febrile UTIs in children and identify children at risk for RS are of primary importance.

Despite its importance being acknowledged in a plethora of studies, developing reading strategies appears absent from many classrooms, which justifies a considerable research interest in this topic. The present study aims to investigate how gender, nationality, and grade point average affect the frequency of the usage of different types of reading strategies among Bosnian university students. The research sample comprised 228 students studying at three universities in Bosnia and Herzegovina. The analysis revealed moderate to high awareness of reading strategies, the problem-solving strategies being most frequently used. A three-way ANOVA showed a significant main effect of gender as well as a significant interaction effect of Nationality × Grade Point Average on The Survey of Reading Strategies questionnaire. Moreover, a three-way MANOVA revealed that gender had a significant main effect on the combined variables, namely global, support, and problem-solving reading strategies. Similarly, the interaction effect of Nationality × Grade Point Average was significant on the three combined variables, while the interaction effects of Grade Point Average × Gender and Grade Point Average × Nationality proved significant only on the Problem-Solving subscale. The current study is expected to contribute to understanding the reading strategy use in a foreign language context, and to inspire educators to recognize the importance of their use in the classroom.

The aim of this paper is to summarize a large number of economic and demographic determinants that are used to predict the demand for life insurance into a smaller number of component variables (components) and to determine which component has a stronger influence on demand for life insurance. Data are collected for 150 countries during the period 2005-2010. Final cross-country database is consisted of six-year average values on variables for selected countries. The methodology includes techniques of multivariate analysis: principal component analysis (PCA) and multiple linear regression. Results show that initial determinants of demand for life insurance can be summarized into two components: economic and demographic. Both components have a statistically significant positive influence on the demand for life insurance. On the basis of standardized regression coefficients it can be concluded that economic component is stronger determinant of demand for life insurance in comparison with demographic.