Introduction: Inappropriate design of experimental studies in medicine inevitably leads to inaccurate or false results, which serve as basis for erroneous and biased conclusions. Aim The aim of our study was to investigate prevalence of implementing basic principles of experimental design (local control, replication and randomization) in preclinical experimental studies, performed either on animals in vivo, or animal/human material in vitro. Material and Methods Preclinical experimental studies were retrieved from the PubMed database, and the sample for analysis was randomly chosen from the retrieved publications. Implementation rate of basic experimental research principles (local control, randomization and replication) was established by careful reading of the sampled publications and their checking against predefined criteria. Results Our study showed that only a minority of experimental preclinical studies had basic principles of design completely implemented (7%), while implementation rate of single aspects of appropriate experimental design varied from as low as 9% to maximum 86%. Average impact factor of the surveyed studies was high, and publication date relatively recent, suggesting generalizability of our results to highly ranked contemporary journals. Conclusion Prevalence of experimental preclinical studies that did not implement completely basic principles of research design is high, raising suspicion to validity of their results. If incorrect and biased, results of published studies may mislead authors of future studies and cause conduction of fruitless research that will waste precious resources.

Nakagami-m probability density function (pdf) is one of the frequently used distributions for describing fast received signal variations in radio channels, obtained as a result of multipath phenomenon. It is foremost derived by assuming the most general multipath channel model but applying mathematical approximations. Afterward, it is derived without approximations, but based on dedicated physical models with many constraints. Consequently, neither approach can be considered both, universally applicable and exact. Accordingly, in this paper, a novel approach in deriving Nakagami-m pdf is provided, being based on fewer constraints on propagation phenomena than others. Herein, it is shown that Nakagami-m pdf can be obtained as a distribution of a Euclidean distance of a point orthogonally projected from homogeneous distributed n-dimensional hypersphere on N-dimensional space, where received signal envelope is interpreted as mentioned Euclidean distance, with $n$ being a total number of orthogonal multipath components which can reach the receiver in idealized condition and $N$ being a number of these components which reach the receiver in reality (with N < n).

The self-blast type circuit breaker has been developed to reduce mechanical operation energy by building up the pressure of arc extinguishing gas flow from the heat of the arc itself. Unlike a puffer type, breaking performance for self-blast type are influenced and sensitive by various factors inside interrupter parts, such as the nozzle structure, chamber shape as well as amplitude of short circuit current. These days, particularly, it has been difficult to secure a low current breaking performance as the circuit breaker has been compacted. The currents for breaking test duties belong to from 10% to 30% of the rated breaking current in accordance with IEC standard. Although the arc energy for interruption is lower than the rated breaking current test duties, the breaking performance could be lower than the tests because the transient recovery voltage (TRV) after the current zero is relatively high. The capability of interruption is related to dielectric recovery after the arc quenching. Therefore, a complex analytical method is needed to secure the breaking performance for the current and to improve the performance by using the limited gas flow inside the interrupter parts. In this paper, it described the techniques to verify breaking performance such as hot gas flow analysis and dielectric analysis. And it has studied a method for improving the performance with various design parameters using computational fluid dynamics (CFD) programs and high power laboratory test. Finally, this paper shows us the improvement of dielectric recovery performance for the self-blast type circuit breaker.

The breakdown voltage during interruption of capacitive currents is defined by two physical quantities: the electric field and the gas density field, which are calculated in different calculation domains and using different mashes. In order to calculate the breakdown voltage, it is necessary to map these two mashes and calculate the ratio density/electric field in every calculation point. The straightforward solution is to pair each density cell with the nearest cell from the electric field mesh, based on their coordinates. Although this solution gives good results, it is very time consuming. Therefore, this paper presents a new approach for mapping of two meshes based on the algebra of fractal vector, so called Bosnian algebra. This approach does not search the meshes for the closest pair based on the coordinates of each point, but instead uses only the assigned cell indexes and simple fractal operations to determine the neighboring cells. This way, the search for the nearest pair is much more efficient and faster.

In this work we will show a novel method for improving the performance of content-based image retrieval using a deep neural network. The main focus of the method is training the distance function using the deep neural network and transfer learning. An existing pretrained network for image classification is used as a basis. One of the method's benefits is the fact that the existing network is not retrained and features for the distance function are the neural network's layers which were trained and stored before. The method is tested with the publicly available VGG19 deep neural network. Obtained results are comparable or in some cases better than the state of the art methods with a similar approach.

Background Mirror aneurysms represent 2 adjacent arterial protrusions. Although the size is considered a major risk factor in terms of rupture, sometimes it is the smaller aneurysm that ruptures. Here, we present the contemporary management of mirror distal anterior cerebral artery (DACA) aneurysms associated with multiple aneurysms. Computational fluid dynamic (CFD) analysis was performed when assessing multiple aneurysms using Hemoscope, version 2015. Case Description Among multiple aneurysms, a mirror A2/A3 DACA aneurysm was found in a single patient. Surgical treatment was provided for all aneurysms through a single-stage procedure. The left ruptured A2/A3 aneurysm was smaller compared with the right (7.5 × 3.5 mm/10.8 × 3.2 mm). CFD showed greater wall pressure (WP) in the left ruptured A2/A3 aneurysm (left A2/A3 WP 84,000–84,402 Inst. mm Hg/right A2/3 WP 84,224–84,315). WP in the left middle cerebral artery and anterior communicating artery aneurysms showed lesser values compared with the ruptured aneurysm (WP upper values 84,361 and 84,367, respectively). Wall shear stress showed low values for all aneurysms with the lowest flow rate values in the left A2/A3 aneurysm. Conclusions In cases of ruptured mirror aneurysms followed by the presence of intracerebral hematoma, surgery is considered the primary option with the best results. A one-stage dual craniotomy procedure was found safe in the associated treatment of other multiple aneurysms. At present, the size of the aneurysm, the hemodynamic influence, and the local configuration are all considerations during the preoperative assessment of multiple aneurysm cases. According to our knowledge, this article presents the first CFD analysis of mirror DACA aneurysms associated with aneurysm multiplicity.

Abstract The aim of the paper is to reveal that humour processing is an exertion which requires both, mental and emotional capacities. To prove the point, two theories for humour processing were employed: the conceptual integration theory and the benign violation theory. The paper shows that theories, though different, possess certain common elements and represent useful tools in humour processing. The conceptual integration theory, with its input spaces, blending processes and generic space, together with the benign violation theory and its detection of humorous elements within tragic situations, could be valuable assets in understanding how people find humour in intimidating and life-threatening situations. The paper also sheds some light on how different age groups perceive black humour showing that age and life experience facilitate understanding of black humour.

Group recommender systems generate recommendations for a group by aggregating individual members’ preferences and finding items that are liked by most of the members. In this paper we introduce a new approach to preference aggregation and group choice prediction that is based on a new form of weighting individuals’ preferences. The approach is based on network science, and, in particular, it relies on the computation of node centrality scores in preferences similarity networks of groups. We also motivate and introduce a non-linear (exponential) remapping of the individuals’ preferences. Based on offline experiments we demonstrate: 1) non-linear remapping of preferences is useful to better predict group choices and generate recommendations; and 2) our weighted approach predicts the actual group choices more accurately than current state-of-the-art methods for group recommendations.CCS CONCEPTS• Information systems → Recommender systems; • Humancentered computing → User studies; User models; Social network analysis.

Teleoperation of multi-robot systems, e.g. dual manipulators, in cooperative manipulation tasks requires haptic feedback of multi-contact interaction forces. Classical haptic devices restrict the workspace of the human operator and provide only one contact point. An alternative solution is to enable the operator to command the robot system via free-hand motions which extends the workspace of the human. In such a setting, a multi-contact haptic feedback may be provided to the human through multiple wearable haptic devices, e.g. fingertip devices that display forces on the human fingertips. In this paper we evaluate the benefit of using wearable haptic fingertip devices to interact with a bimanual robot setup in a pick-and-place manipulation task. We show that haptic feedback through wearable devices improves task performance compared to the base condition of no haptic feedback. Therefore, wearable haptic devices are a promising interface for guidance of multi-robot manipulation systems.

Smart Ecosystem reflects in the control decisions of entities of different nature, especially of its software components. Particularly, the malicious behavior requires a more accurate attention. This paper discusses the challenges related to the evaluation of software smart agents and proposes a first solution leveraging the monitoring facilities for a) assuring conformity between the software agent and its digital twin in a real-time evaluation and b) validating decisions of the digital twins during runtime in a predictive simulation.

Introduction: Neurophysiological tests allow accurate assessment of the function of the peripheral nervous system. Detection of neurophysiological changes allows us to understand the neurological clinical symptoms and signs of patients with type 1 and type 2 diabetes and the possibility for their symptomatic treatment. Aim: Evaluate the effect of diabetes mellitus on the “cutaneous silent period” in detecting diabetic polyneuropathy. Material and Methods: The study included 150 subjects, 90 suffering from diabetes, divided into three groups of 30, depending on the disease duration, and a control group of 60 respondents not suffering from diabetes or other polyneuropathies. The control group are referred for EMG analysis on another basis (cervical radiculopathy, brachialgia, etc.). Group 1 consisted of 30 subjects with diabetes mellitus type 2 and duration of illness up to 5 years. Group 2 consisted of 30 subjects with type 2 diabetes mellitus 2 and illness duration from 5 to 10 years. Group 3 consisted of 30 patients with type 1 diabetes mellitus. The study groups consisted of patients referred for EMNG analysis to the EMG office of the Clinical Center of Sarajevo University, Neurology Clinic and the Neurophysiology Laboratory in Ljubljana, from July 1, 2011 to May 1, 2016. All patients were examined neurologically and electroneurographic analysis was performed. Results: A statistically significant difference was found in the incidence of pathologic CSP with respect to the study groups, χ2 = 26.153; p=0.001. Pathologic CSP was more common in group 1 and group 2 of subjects (56.17%) compared to group 3 and control subjects, where it occurred in 13.3% of the cases. Conclusion: The pathological cutaneous period of silence was more frequent in subjects of group 1 and group 2, that is, in subjects with DM type 2, compared to subjects with DM type 1.