Верифікація підсумкових ранжувань, отриманих внаслідок експертного оцінювання

In the modern dynamic information society, situations that are characterized by complexity, multifactoriality, uncertainty, and non-formalization occur very often. Under such conditions, the adoption of effective management decisions is impossible without interaction with the expert environment. This applies to a wide range of human activities, including economic issues. The article is devoted to one of the key stages of expert evaluation – the analysis of members of expert commissions’ judgments and drawing up final conclusions. The author aims to get closer to solving one of the key problems characteristic to this stage, namely: truth verification problems, reliability confirmation for final conclusions obtained as a result of generalization of expert groups’ work. Most often, the experts are asked to compare certain objects according to certain criteria, to identify the best and the worst among them. It is clear that expert judgments are rarely unanimous. Therefore, it is important to apply scientific approaches to constructing final ranking, that is, the final location of objects in order of increase or decrease of a certain quality or usability. The mathematical modeling of activity of an expert group conducted by the author of the article made it possible to identify cases where, depending on the applied techniques, the final rankings obtained on the basis of the judgments of the same experts may differ (sometimes even substantially). This again emphasizes the need to verify the final rankings. The advantages and disadvantages of applying quantitative and qualitative methods in expert-analytical activity are also considered. The scientific novelty of the conducted research is to improve the methodological approaches that will allow to improve the consistency of expert judgments, and to develop recommendations for the complex application of separate methods for constructing total ranking. The article is intended for scientists and practitioners who are interested in contemporary sociological and management approaches to solving economic problems. Also, the article may be useful for specialists and programmers who work in the field of development of artificial intelligence.У сучасному динамічному інформаційному суспільстві дуже часто виникають ситуації, які характеризуються складністю, багатофакторністю, невизначеністю, неформалізованістю. За таких умов ухвалення ефективних управлінських рішень є неможливим без взаємодії з експертним середовищем. Це стосується найрізноманітніших сфер людської діяльності, у тому числі й економічних питань. Стаття присвячена одній з ключових стадій експертного оцінювання – аналізу суджень членів експертних комісій. виробленню остаточних висновків. Автор ставить за мету наблизитись до розв’язання однієї з ключових проблем, притаманних цій стадії, а саме: проблеми перевірки істинності, підтвердження достовірності тих остаточних висновків, які отримуються в результаті узагальнення роботи експертних груп. Найчастіше перед експертами ставиться завдання порівняти за визначеними критеріями певні об’єкти, виявити найкращі та найгірші серед них. Зрозуміло, що експертні судження нечасто виявляються одностайними. Тому важливо застосувати наукові підходи до побудови підсумкових ранжувань, тобто заключного розташування об’єктів в порядку зростання чи спадання певної якості чи придатності до застосування. Проведене автором статті математичне моделювання діяльності експертної групи дозволило  виявити випадки, коли в залежності від застосованих методик підсумкові ранжування, отримані на основі суджень одних і тих же експертів, можуть відрізнятись (часом навіть суттєво). Це ще раз підкреслює необхідність верифікації підсумкових ранжувань. Також розглядаються переваги та недоліки застосування кількісних і якісних методів в експертно-аналітичній діяльності. Наукова новизна проведених досліджень полягає у вдосконаленні методологічних підходів, які дозволять покращити узгодженість експертних суджень, і виробленні рекомендацій стосовно комплексного застосування окремих методів побудови підсумкових ранжувань. Стаття призначена для науковців та практиків, яких цікавлять сучасні соціологічні та управлінські підходи до вирішення економічних проблем. Також стаття може бути корисною для фахівців та програмістів, які працюють у сфері розроблення штучного інтелекту

Magnetic properties and magnetostructural phase transitions in Ni2+xMn1-xGa shape memory alloys

A systematic study of magnetic properties of Ni2+xMn1-xGa (0 \le x \le 0.19) Heusler alloys undergoing structural martensite-austenite transformations while in ferromagnetic state has been performed. From measurements of spontaneous magnetization, Ms(T), jumps \Delta M at structural phase transitions were determined. Virtual Curie temperatures of the martensite were estimated from the comparison of magnetization in martensitic and austenitic phases. Both saturation magnetic moments in ferromagnetic state and effective magnetic moments in paramagnetic state of Mn and Ni atoms were estimated and the influence of delocalization effects on magnetism in these alloys was discussed. The experimental results obtained show that the shift of martensitic transition temperature depends weakly on composition. The values of this shift are in good correspondence with Clapeyron-Clausius formalism taking into account the experimental data on latent heat at martensite-austenite transformations.Comment: 7 pages, 8 figure

Origin of four-fold anisotropy in square lattices of circular ferromagnetic dots

We discuss the four-fold anisotropy of in-plane ferromagnetic resonance (FMR) field $H_r$, found in a square lattice of circular Permalloy dots when the interdot distance $a$ gets comparable to the dot diameter $d$. The minimum $H_r$, along the lattice $$axes, and the maximum, along the$$ axes, differ by $\sim$ 50 Oe at $a/d$ = 1.1. This anisotropy, not expected in uniformly magnetized dots, is explained by a non-uniform magnetization \bm(\br) in a dot in response to dipolar forces in the patterned magnetic structure. It is well described by an iterative solution of a continuous variational procedure.Comment: 4 pages, 3 figures, revtex, details of analytic calculation and new references are adde

Magnetic Vortex Resonance in Patterned Ferromagnetic Dots

We report a high-resolution experimental detection of the resonant behavior of magnetic vortices confined in small disk-shaped ferromagnetic dots. The samples are magnetically soft Fe-Ni disks of diameter 1.1 and 2.2 um, and thickness 20 and 40 nm patterned via electron beam lithography onto microwave co-planar waveguides. The vortex excitation spectra were probed by a vector network analyzer operating in reflection mode, which records the derivative of the real and the imaginary impedance as a function of frequency. The spectra show well-defined resonance peaks in magnetic fields smaller than the characteristic vortex annihilation field. Resonances at 162 and 272 MHz were detected for 2.2 and 1.1 um disks with thickness 40 nm, respectively. A resonance peak at 83 MHz was detected for 20-nm thick, 2-um diameter disks. The resonance frequencies exhibit weak field dependence, and scale as a function of the dot geometrical aspect ratio. The measured frequencies are well described by micromagnetic and analytical calculations that rely only on known properties of the dots (such as the dot diameter, thickness, saturation magnetization, and exchange stiffness constant) without any adjustable parameters. We find that the observed resonance originates from the translational motion of the magnetic vortex core.Comment: submitted to PRB, 17 pages, 5 Fig

Soliton pair dynamics in patterned ferromagnetic ellipses

Confinement alters the energy landscape of nanoscale magnets, leading to the appearance of unusual magnetic states, such as vortices, for example. Many basic questions concerning dynamical and interaction effects remain unanswered, and nanomagnets are convenient model systems for studying these fundamental physical phenomena. A single vortex in restricted geometry, also known as a non-localized soliton, possesses a characteristic translational excitation mode that corresponds to spiral-like motion of the vortex core around its equilibrium position. Here, we investigate, by a microwave reflection technique, the dynamics of magnetic soliton pairs confined in lithographically defined, ferromagnetic Permalloy ellipses. Through a comparison with micromagnetic simulations, the observed strong resonances in the subgigahertz frequency range can be assigned to the translational modes of vortex pairs with parallel or antiparallel core polarizations. Vortex polarizations play a negligible role in the static interaction between two vortices, but their effect dominates the dynamics.Comment: supplemental movies on http://www.nature.com/nphys/journal/v1/n3/suppinfo/nphys173_S1.htm

Low-loss Si-based Dielectrics for High Frequency Components of Superconducting Detectors

Silicon-based dielectric is crucial for many superconducting devices, including high-frequency transmission lines, filters, and resonators. Defects and contaminants in the amorphous dielectric and at the interfaces between the dielectric and metal layers can cause microwave losses and degrade device performance. Optimization of the dielectric fabrication, device structure, and surface morphology can help mitigate this problem. We present the fabrication of silicon oxide and nitride thin film dielectrics. We then characterized them using Scanning Electron Microscopy, Atomic Force Microscopy, and spectrophotometry techniques. The samples were synthesized using various deposition methods, including Plasma-Enhanced Chemical Vapor Deposition and magnetron sputtering. The films morphology and structure were modified by adjusting the deposition pressure and gas flow. The resulting films were used in superconducting resonant systems consisting of planar inductors and capacitors. Measurements of the resonator properties, including their quality factor, were performed.Comment: 4 pages, 5 figures, conferenc

Failure of noninvasive prediction of pulmonary hypertension in patients with idiopathic pulmonary fibrosis

Background. Pulmonary hypertension (PH) in patients with advanced idiopathic pulmonary fibrosis (IPF) is a complication connected with unfavorable prognosis. Great efforts have been made in attempting to establish a reliable non-invasive method which would enable detection of this complication. In this context a formula using pulmonary function parameters was published with outstanding results. Methods. We tested the formula in 27 IPF patients who underwent a lung function examination, cardiac ultrasonography and catheterisation on the same day. Results. Pulmonary hypertension was detected by catheterisation in 17 patients (63%). In our group, contrary to the published data, the aforementioned formula was neither useful for detecting patients with a high probability of PH nor as a means of calculating the mean pulmonary artery pressure in individual patients (p=0.502 and p=0.833, respectively). Ultrasound examination reached borderline correlation with the values measured by catheterisation when we compare patients with relevant results (r=0.531, p=0.051). However, the examination gave no usable results in 13 patients (48%). Conclusion. Our data suggests that no reliable, noninvasive method is currently available for detecting and confirming PH in IPF patients. We did not confirm the usefulness of the published formula. Further carefully organised studies will be necessary to verify or refute it