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Search results for: ITERATIVE REWEIGHTING
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Performance evaluation of unified memory and dynamic parallelism for selected parallel CUDA applications
PublicationThe aim of this paper is to evaluate performance of new CUDA mechanisms—unified memory and dynamic parallelism for real parallel applications compared to standard CUDA API versions. In order to gain insight into performance of these mechanisms, we decided to implement three applications with control and data flow typical of SPMD, geometric SPMD and divide-and-conquer schemes, which were then used for tests and experiments. Specifically,...
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TF-IDF weighted bag-of-words preprocessed text documents from Simple English Wikipedia
Open Research DataThe SimpleWiki2K-scores dataset contains TF-IDF weighted bag-of-words preprocessed text documents (raw strings are not available) [feature matrix] and their multi-label assignments [label-matrix]. Label scores for each document are also provided for an enhanced multi-label KNN [1] and LEML [2] classifiers. The aim of the dataset is to establish a benchmark...
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Grid-Forming Operation of Energy-Router Based on Model Predictive Control with Improved Dynamic Performance
PublicationThe focus of this study is on the grid-forming operation of the Energy Router (ER) based on Model Predictive Control (MPC). ER is regarded as a key component of microgrids. It is a converter that interfaces the microgrid (s) with the utility grid. The ER has a multiport structure and bidirectional energy flow control. The ER concept can be implemented in Nearly Zero-Energy Buildings (NZEB) to provide flexible energy control. A...
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E-experiments in physics. Proper business process management, collaborative development process and project management guidance – remedy for avoiding the main IT project’s failure
PublicationOnly a few of learning aids and simulations of physical phenomena allow for building interactive experiments; experiments similar to those that should be conducted in physics laboratories at schools. Group of staff from Gdansk University of Technology decided to fill this market niche by designing and constructing a set of virtual experiments – so called e-experiments. To avoid common problems that a lot of IT products brought...
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Utilising IT-based systems in regatta management
PublicationThe development and increasing accessibility of new technologies has brought changes to the management of sailing regattas. Organisational and promotional difficulties faced by the organisers are now being tackled with software-based systems. This article considers various information technology (IT) systems, designed to support the organisation and presentation of sailing regattas and explores how they are perceived by regatta...
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Good practices in requirements, project and risk managment in educational IT projects
PublicationOne can find many learning aids and simulations of physical phenomena on the market - provided as a standalone application or as part of an educational package. However, only a few of them allow for the building of interactive experiments: experiments similar to those that should be conducted in physics laboratories at schools. Gdańsk University of Technology decided to fill this market niche by designing and constructing a set...
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ASSESSMENT OF VOLATILE ORGANIC COMPOUNDS EMISSIONS FROM RECYCLED LOW-DENSITY POLYETHYLENE STREAMS
PublicationThe recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for the potential methods of their utilization. Nevertheless, it should not be forgotten that recycled plastics are not pure materials, and they still may show an unfavorable environmental impact. They may contain different contaminants...
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The Lost Kinetic Architecture and How to Reintroduce it in the Landscape – The Case Study of the Drainage Windmills in the Vistula Delta
PublicationRecreating the lost kinetic landscape of the Vistula Delta is a considerable challenge. The study aims to propose a method for reproducing windmills and their effect on the landscape. The paper suggests a method based on the transposition of the forms of movement from windmills historically present in the region to modern forms. The method is based on a series of analyses starting with the study of the region and its history followed...
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The potential of Web-GIS and geovisual analytics in the context of marine cadastre
PublicationThe importance of the marine environment to human existence makes it imperative that information models represent the multidimensional nature of reality as closely as possible in order to facilitate good governance. Information regarding jurisdiction, as well as the effects of formal law and community interests on the marine environment (e.g. nature and spatial extents as well as rights, responsibilities, restrictions etc.) would...
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Atomistic Surrogate-Based Optimization for Simulation-Driven Design of Computationally Expensive Microwave Circuits with Compact Footprints
PublicationA robust simulation-driven design methodology for computationally expensive microwave circuits with compact footprints has been presented. The general method introduced in this chapter is suitable for a wide class of N-port un-conventional microwave circuits constructed as a deviation from classic design solutions. Conventional electromagnetic (EM) simulation-driven design routines are generally prohibitive when applied to numerically...
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Efficient knowledge-based optimization of expensive computational models using adaptive response correction
PublicationComputer simulation has become an indispensable tool in engineering design as they allow an accurate evaluation of the system performance. This is critical in order to carry out the design process in a reliable manner without costly prototyping and physical measurements. However, high-fidelity computer simulations are computationally expensive. This turns to be a fundamental bottleneck when it comes to design automation using numerical...
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STUDY ON THE RELATIONSHIP BETWEEN VEHICLE MAINTENANCE AND FUEL CONSUMPTION
PublicationA contemporary road vehicle (RV) is a rather complex system, consisting of a large number of subsystems, assemblies, units, and elements (parts). While operating, an RV interacts with the environment, and its elements interact with each other. Consequently, the properties (parameters) of these elements change in the process - hardness, roughness, size, relative position, gapping, etc. A partial solution to the presented problems...
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Numerical and experimental investigation of guided ultrasonic wave propagation in non-uniform plates with structural phase variations
PublicationThe article presents the results of numerical and experimental investigations of guided wave propagation in aluminum plates with variable thickness. The shapes of plate surfaces have been specially designed and manufactured using a CNC milling machine. The shapes of the plates were defined by sinusoidal functions varying in phase shift, which forced the changes in thickness variability alongside the propagation path. The main aim...
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Comparative analysis of mechanical conditions in bone union following first metatarsophalangeal joint arthrodesis with varied locking plate positions: A finite element analysis
PublicationFirst metatarsophalangeal joint arthrodesis is a typical medical treatment performed in cases of arthritis or joint deformity. The gold standard for this procedure is arthrodesis stabilisation with the dorsally positioned plate. However, according to the authors’ previous studies, medially positioned plate provides greater bending stiffness. It is worth to compare the mechanical conditions for bone formation in the fracture callus...
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Generalized Pareto ranking bisection for computationally feasible multi-objective antenna optimization
PublicationMulti-objective optimization (MO) allows for obtaining comprehensive information about possible design trade-offs of a given antenna structure. Yet, executing MO using the most popular class of techniques, population-based metaheuristics, may be computationally prohibitive when full-wave EM analysis is utilized for antenna evaluation. In this work, a low-cost and fully deterministic MO methodology is introduced. The proposed generalized...
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A GPU Solver for Sparse Generalized Eigenvalue Problems with Symmetric Complex-Valued Matrices Obtained Using Higher-Order FEM
PublicationThe paper discusses a fast implementation of the stabilized locally optimal block preconditioned conjugate gradient (sLOBPCG) method, using a hierarchical multilevel preconditioner to solve nonHermitian sparse generalized eigenvalue problems with large symmetric complex-valued matrices obtained using the higher-order finite-element method (FEM), applied to the analysis of a microwave resonator. The resonant frequencies of the low-order...
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NUMERICAL ESTIMATION OF HULL HYDRODYNAMIC DERIVATIVES IN SHIP MANOUVERING PREDICTION
PublicationOperating in crowded waterways pose a risk of accidents and disasters due to maneuvering limitations of the ship. In order to predict ship’s maneuvering characteristics at the design stage, model tests are often executed as the most accurate prediction tool. Two approaches can be distinguished here: free running model tests and numerical simulations based on planar motion model with the use of hydrodynamic derivatives obtained...
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FIR Filter Design Using Distributed Maximal Flatness Method
PublicationIn the paper a novel method for filter design based on the distributed maximal flatness method is presented. The proposed approach is based on the method used to design the most common FIR fractional delay filter - the maximally flat filter. The MF filter demonstrates excellent performance but only in a relatively narrow frequency range around zero frequency but its magnitude response is no greater than one. This ,,passiveness”...
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Sleep apnea: epidemiology, pathophysiology, and relation to cardiovascular risk
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Monitoring of breast tissue thermo-ablation by means of impedance measurements
PublicationW pracy przedstawiono rozważania dotyczące monitorowania jakości termoablacji zmian nowotworowych w piersi przy pomocy pomiarów impedancyjnych. Pokazano prototypowe konstrukcje sond do termoablacji jak również zaprezentowano wyniki symulacji i pierwszych eksperymentów. A usefulness of a developed probe combining power delivery to ablated breast tumour and simultaneous impedance measurements is discussed in the paper. It consists...
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Cross-domain applications of multimodal human-computer interfaces
PublicationDeveloped multimodal interfaces for education applications and for disabled people are presented, including interactive electronic whiteboard based on video image analysis, application for controlling computers with mouth gestures and audio interface for speech stretching for hearing impaired and stuttering people and intelligent pen allowing for diagnosing and ameliorating developmental dyslexia. The eye-gaze tracking system named...
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Towards the value-based design of on-line services
PublicationThe paper identifies economic factors shaping customer bahaviour in on-line services in two interrelated dimensions; (1) economic needs and requirements, relevant to expected benefits and values perceived by customers; (2) technical components, allowing technical realization of on-line services. Technical components were cathegorized into four groups, creating so-called VIPR model: Visual, Interactive, Process and Relationship-relevant...
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Integration of natural and artificial intelligence in production systems
PublicationIntegration processes play an increasingly important role in modern economy, and seriously co-decide about the effectiveness of the company. Integration phase occurs in the system life cycle by preceding the final stages of its implementation and activation. In turn, used in software engineering (SE) iteration-evolutionary models, such as spiral model make that the integration activities can occur in varying degrees in all phases...
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Rapid design closure of linear microstrip antenna array apertures using response features
PublicationA simple yet reliable approach to a rapid design closure of linear antenna array apertures at the electromagnetic (EM)-simulation level is proposed. Our methodology exploits an underlying array factor (AF) model suitably corrected by means of characteristic points (angles and levels) of the radiation pattern of the EM model of the antenna array aperture. This conveniently allows for controlling both the side lobe levels...
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Expedited Design Closure of Antennas By Means Of Trust-Region-Based Adaptive Response Scaling
PublicationIn the letter, a reliable procedure for expedited design optimization of antenna structures by means of trust-region adaptive response scaling (TR-ARS) is proposed. The presented approach exploits two-level electromagnetic (EM) simulation models. A predicted high-fidelity model response is obtained by applying nonlinear frequency and amplitude correction to the low-fidelity model. The surrogate created this way is iteratively rebuilt...
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State-of-the-art ideas for engineering laboratory classes – virtual reality framework
PublicationNowadays challenges in science and technology are a driving force in the development of contemporary solutions in education. Virtual reality brings to an edge human imagination. In this paper, authors propose a framework for civil engineering laboratory classes which brings a new quality in this area. The framework shows how to provide learners with an environment where they can realize the health and safety hazards of construction...
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Architectural education and digital tools: the challenges and opportunities
PublicationEnriching architectural education with digital tools is the subject of this article. Such tools can create, support and visualise architecture. The focus in this article is on an interdisciplinary approach to media architecture (allowing variable visual content of architectural objects) and interactivity (user-space communication), revealing new possibilities in terms of human perception. The results of a survey on media architecture...
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Social Entrepreneurship Avenues for the Field Development through Research Paradigm Intersection Discussion
PublicationThe aim of this paper is to identify and provide key arguments for employing integrative approach in the choice of research paradigm for studying social entrepreneurship phenomenon. The fact that social entrepreneurship as a field of research is at its preliminary stage, serves as argument and gives freedom in the discussion of the choice of employing a research paradigm. The author does so through identifying commonalities and...
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Simulation of the weight averaging of pulse frequency modulated sensor output signal
Open Research DataThe aim of the research is investigation of the efficiency of weight averaging of pulse frequency modulated signal. It was shown that from the point of view of the reduction of the sampling error the best are polynomial weighing functions, for which the maximum of this component error decreases proportionally to the appropriate power of the number of...
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Jerzy Redlarski mgr inż.
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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublicationVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Generation of large finite-element matrices on multiple graphics processors
PublicationThis paper presents techniques for generating very large finite-element matrices on a multicore workstation equipped with several graphics processing units (GPUs). To overcome the low memory size limitation of the GPUs, and at the same time to accelerate the generation process, we propose to generate the large sparse linear systems arising in finite-element analysis in an iterative manner on several GPUs and to use the graphics...
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Computationally Efficient Design Optimization of Compact Microwave and Antenna Structures
PublicationMiniaturization is one of the important concerns of contemporary wireless communication systems, especially regarding their passive microwave components, such as filters, couplers, power dividers, etc., as well as antennas. It is also very challenging, because adequate performance evaluation of such components requires full-wave electromagnetic (EM) simulation, which is computationally expensive. Although high-fidelity EM analysis...
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Badanie wpływu strategii sterowania obiegiem narzędzi na wydajność elastycznego systemu wytwarzania.
PublicationPrzedmiotem rozprawy doktorskiej są badania wpływu strategii sterowania obiegiem narzędzi na wydajność elastycznego systemu wytwarzania. Obiektem badań było elastyczne gniazdo obróbkowe wyposażone w trzy poziome frezarsko-wytaczarskie centra obróbkowe przeznaczone do wytwarzania części klasy korpus. Wybrane strategie przydziału operacji technologicznych i adekwatnych zestawów narzędziowych poddano analizie i ocenie wg przyjętych...
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Healthier and Environmentally Responsible Sustainable Cities and Communities. A New Design Framework and Planning Approach for Urban Illumination
PublicationAlthough sustainability and sustainable development are both considered necessary practices in various fields today, a recent analysis showed that the Sustainable Development Goal SDG11: Sustainable Cities and Communities established by the United Nations does not address urban illumination and its impact. This oversight is of concern because research carried out in the last 20+ years indicates artificial light at night (ALAN)...
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Inverse Nonlinear Eigenvalue Problem Framework for the Synthesis of Coupled-Resonator Filters With Nonresonant Nodes and Arbitrary Frequency-Variant Reactive Couplings
PublicationA novel, general circuit-level description of coupledresonator microwave filters is introduced in this article. Unlike well-established coupling-matrix models based on frequency-invariant couplings or linear frequency-variant couplings (LFVCs), a model with arbitrary reactive frequencyvariant coupling (AFVC) networks is proposed. The engineered formulation is more general than prior-art ones—with the only restriction that the coupling...
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DL_MG: A Parallel Multigrid Poisson and Poisson–Boltzmann Solver for Electronic Structure Calculations in Vacuum and Solution
PublicationThe solution of the Poisson equation is a crucial step in electronic structure calculations, yielding the electrostatic potential -- a key component of the quantum mechanical Hamiltonian. In recent decades, theoretical advances and increases in computer performance have made it possible to simulate the electronic structure of extended systems in complex environments. This requires the solution of more complicated variants of the...
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Expedited Acquisition of Database Designs for Reduced-Cost Performance-Driven Modeling and Rapid Dimension Scaling of Antenna Structures
PublicationFast replacement models have been playing an increasing role in high-frequency electronics, including the design of antenna structures. Their role is to improve computational efficiency of the procedures that normally entail large numbers of expensive full-wave electromagnetic (EM) simulations, e.g., parametric optimization or uncertainty quantification. Recently introduced performance-driven modeling methods, such as the nested...
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Simulating propagation of coherent light in random media using the Fredholm type integral equation
PublicationStudying propagation of light in random scattering materials is important for both basic and applied research. Such studies often require usage of numerical method for simulating behavior of light beams in random media. However, if such simulations require consideration of coherence properties of light, they may become a complex numerical problems. There are well established methods for simulating multiple scattering of light (e.g....
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Badanie aktywności online polskich konsumentów dotyczącej marek
PublicationRozwój nowych trendów w internecie, a w szczególności Web 2.0, spowodował wzrost społecznego zaangażowania internautów oraz dalszy rozwój kanałów społecznościowych i tym samym różnego typu platform interaktywnych. Internet zachęca internautów do interakcji z witrynami, a za ich pośrednictwem z innymi użytkownikami sieci. Umożliwia im tworzenie treści na temat różne tematy, w tym na przykład związany z markami produktów. Dzięki...
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Możliwości wyszukiwania dokumentów muzycznych utworzonych zgodnie z architekturą IODA
PublicationArtykuł przedstawia zagadnienie zastosowania dokumentów muzycznych utworzonych zgodnie z architekturą IODA (ang. Interactive Open Document Architecture). Dokumenty w architekturze IODA składają się z wielu plików powiązanych ze sobą semantycznie. Zależności te definiowane są w tzw. grzbiecie (ang. spine) dokumentu będącym plikiem w formacie XML (ang. eXtensible Markup Language). Dokumenty muzyczne tworzone zgodnie z architekturą...
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Analysis of the Environmental Impact of the Hull Construction of a Small Vessel Based on LCA
PublicationIn recent years, issues related to the impact of human activity on the natural environment have become pressing, and the challenge of global warming necessitates immediate action. To support environmental protection efforts, it has become imperative to adopt a broader perspective when evaluating various products and systems. A valuable tool for such assessments is a life cycle assessment (LCA), which enables a comprehensive analysis...
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Position and Orientation Estimation in Radio Network With Groups of Locally Synchronized Nodes
PublicationThis article presents a positioning system with groups of locally synchronized nodes. A mobile object is equipped with a group of several synchronized receivers that are able to measure the difference in the time of arrival of signals from reference transmitters. The reference transmitters are synchronized only in local groups, with no global synchronization between groups. It is assumed that the synchronous operation of transmitters...
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A comparative analysis of numerically simulated and experimentally measured static responses of a floating dock
PublicationTwo numerical methods, dynamic and static analyses, are proposed to calculate the static responses of a floating dock under different ballast water distributions. Model-scale experimental tests were conducted to compare with these numerical methods. The dynamic analysis includes a 6-degree-of-freedom (6-DOF) model, a hydrostatic force model and a hydrodynamic force model to simulate the dock's freely floating processes. The dock's...
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Frequency-Based Regularization for Improved Reliability Optimization of Antenna Structures
PublicationThe paper proposes a modified formulation of antenna parameter tuning problem. The main ingredient of the presented approach is a frequency-based regularization. It allows for smoothening the functional landscape of the assumed cost function, defined to encode the prescribed design specifications. The regularization is implemented as a special penalty term complementing the primary objective and enforcing the alignment of the antenna...
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Smart Document-Centric Processing of Human Oriented Information Flows
PublicationUsually people prefer to focus on creative rather than repetitive and schematic work patterns. Still, they must spend a lot of time complying with the procedures, selecting the information they receive and repeatedly restoring the previous state of work. This paper proposes the Mobile INteractive Document architecture (MIND) - a document-centric uniform interface to provide both effective communication of content and coordination...
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Mechatronics design, modelling and controlling of the Stewart-Gough platform
PublicationThis paper presents a mechatronics design of a low cost Stewart-Gough platform (SGP) with rotary actuators. The designed SGP is supposed to be applied in a ball & plate control system. The synthesis of the ball & plate control system is also within the subject of the paper. A mechatronics design process of the SGP was conducted with computer-aided design (CAD) software. Unique analytical solutions of an inverse kinematics problem...
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Bridging theory and practice in postgraduate education on development and planning: Gdynia Urban Summer Schools 2016-2018
PublicationIn this article, the authors discuss results achieved by the Gdynia Urban Summer School (GUSS) organised annually (between 2016 and 2018) in Gdynia, Poland. The GUSS was meant for young practitioners from various professions such as urban and regional planning, urban design, architecture, civil engineering and transport planning. The objective was to give workshop participantspractical interdisciplinary...
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Nuclear Magnetic Resonance Metabolomics Reveals Qualitative and Quantitative Differences in the Composition of Human Breast Milk and Milk Formulas
PublicationCommercial formula milk (FM) constitutes the best alternative to fulfill the nutritional requirements of infants when breastfeeding is precluded. Here, we present the comparative study of polar metabolite composition of human breast milk (HBM) and seven different brands of FM by nuclear magnetic resonance spectroscopy. The results of the multivariate data analysis exposed qualitative and quantitative differences between HBM and...
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Psychometric assessment of the Internet Gaming Disorder diagnostic criteria: An Item Response Theory study
PublicationInternet Gaming Disorder (IGD) has been recognized by the American Psychiatric Association (APA) as a tentative disorder in the latest fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). In order to advance research on IGD, the APA has suggested that further research on the nine IGD criteria to investigate its clinical and empirical feasibility is necessary. The aim of the present study was to...