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Measurements of Galvanic Skin Response on Subjects Affected by Stress

Abstract

The aim of the present paper is to study the Galvanic Skin Response (GSR) level on subjects affected by stress. The device that we have used, connects to the people by finger electrodes to record GSR. The purpose was to find statistical differences between the activities (mental task, walking, sitting and to fill out a survey about their lives) and their stress level. During the experiment, it was found that the survey caused the source of high stress and increasing skin conductance was caused by sweat secretion (mental, physical activity). Is needed to work of collecting data from more subjects because GSR is depended on human behaviour, is variable upon many factors (their eating habits, their emotional state, their gender, their relationship with family, etc) and we need to build a substantial data set for a valid research.

Open access
Measuring the Moment and the Magnitude of the Abrupt Change of the Gaussian Process Bandwidth

Abstract

The maximum likelihood algorithm is introduced for measuring the unknown moment of abrupt change and bandwidth jump of a fast-fluctuating Gaussian random process. This algorithm can be technically implemented much simpler than the ones obtained by means of common approaches. The technique for calculating the characteristics of the synthesized measurer is presented and the closed analytical expressions for the conditional biases and variances of the resulting estimates are found using the additive local Markov approximation of the decision statistics. By statistical simulation methods, it is confirmed that the presented measurer is operable, while the theoretical formulas describing its performance well approximate the corresponding experimental data in a wide range of the parameter values of the analyzed random process.

Open access
Mechanical Properties of Aluminium Bracket Strengthening

Abstract

The aim of the research is laboratory investigation of aluminium brackets employed to fasten lightweight curtain walls to building facilities. Tensile loads perpendicular to end plates (vertical) were applied here. The author focused on the solutions intended to increase the load-carrying capacity of aluminium brackets applying the plain washer form A (DIN 125; ISO 7089), plain washer with an outer diameter about 3d (DIN 9021; ISO 7093) and additional cover plates (straps) in the location of bolt anchoring on the base plate. The aluminium brackets were tested on a steel base and concrete substrate. The flexibility of anchoring strongly affects the increase of the end plate middle point displacement and movable crosshead displacement.

Open access
Methods of Academic Education in the Field Occupational Safety and Health - Analysis of Applied Solutions in the Opinion of Students, Employees and Employers

Abstract

Methods of education applied at universities have a direct impact on matching of knowledge, skills, but also on the approach to the professional sphere of graduates, in relation to the needs and requirements of employers. It is particularly important in the case of Occupational Safety and Health field of study. Using the available means of technical and informational support of education, one should concentrate on shaping individual thinking. In times of rapid technological development, it is not the duplication that counts, but the creative thinking that must be accompanied by the ability to work in a group. And in this direction, according to the author, academic education should pursue. In the publication, the author analyses the applied methods of education. For this purpose, the results of the study of the participant’s observation, direct interviews with employees and employers, as well as the results of a survey conducted among students of the Czestochowa University of Technology, will be used. The analysis will be carried out in terms of the evaluation of applied methods of education - quality, usefulness, adjustment to expectations (students and employers), attractiveness of form and content.

Open access
Minimum Value Approach for Modelling of the Buckling Resistance of Welded I-Section High Strength Steel Columns

Abstract

The paper deals with determination of flexural resistance buckling curves for welded I-section steel members made of high strength steel (S 690). In the paper the previously proposed BF analytical model is used for approximation of FEM results obtained using moderately large deformation shell theory and ABAQUS/Standard software. Final formulation of flexural resistance buckling curves is possible through the use of the Merchant-Rankine-Murzewski approach adopted extensively in the authors’ previous papers. For nonlinear optimization, which is needed for analytical model parameters determination, the Wolfram Mathematica package is used. Obtained results for S 690 steel are presented against the results for S 355 steel.

Open access
Model of Construction Subcontractors Selection with Time Windows for their Availability

Abstract

Most construction projects involve subcontracting some work packages. A subcontractor is employed on the basis of their bid as well as according to their availability. A viable schedule must account for resource availability constraints. These resources (e.g. crews, subcontractors) engage in many projects, so they become at the disposal for a new project only in certain periods. One of the key tasks of a planner is thus synchronizing the work of resources between concurrent projects. The paper presents a mathematical model of the problem of selecting subcontractors or general contractor’s crews for a time-constrained project that accounts for the availability of contractors, as well as for the cost of subcontracting works. The proposed mixed integer-binary linear programming model enables the user to perform the time/cost trade-off analysis.

Open access
A Model of the Moment Curvature Relation for RC Beams Strengthened with Prestressed CFRP Laminates

Abstract

The paper presents an analysis of the behaviour of bent reinforced concrete beams strengthened with CFRP laminates fixed with adhesive before and after unloading, and more importantly, an analysis of the work of reinforced concrete beams strengthened with pre-stressed CFRP laminates fixed with adhesive. The analyses were based on a moment-curvature model prepared by the author for reinforced concrete beams strengthened under load with pre-stressed CFRP laminates. The model was used to determine the effect of compression with CFRP laminates and their mechanical properties on the effectiveness of strengthening the reinforced concrete beams analysed in this study.

Open access
Modeling and Electrical Characterization of Josephson Junction Using Approximation in the sense of Least Squares

Abstract

In order to be able to realize out the mixing detection or harmonic generation functions, a non-linear circuit is necessary for different existing devices and for performing these types of operation, in the submillimetric and / or far-infrared domains (10 μm ≤ λ ≤ 1 mm), the spectral margin covered by this radiation ranging from 300 GHz to 30 THz. In these frequency domains, non-linear point devices are often used, unlike the optical domain where massive devices are widely used, among them the Josephson Junction (JJ) is mainly used in the case where low noise is desired. This paper present electrical characteristic of Josephson Junction (JJ) using Approximation in the sense of Least Squares, for different value of Cj, T, Rj.

Open access
Multimodality Imaging in Ischemic Cardiomyopathy

Abstract

Ischemic heart disease is the most common heart pathology in medical practice. Proper assessment of the size of myocardium injury and its consequences on the heart function is extremely important both for a correct drug therapy and for interventional approach. Most frequently the left ventricle is affected. The need for accurate evaluation of the impact of left ventricular myocardial damage has led to the development of new imaging techniques and improvement of the existing ones. At the moment the most commonly used imaging method for the assessment of left ventricular function is echocardiography. Cardiac Magnetic Resonance and nuclear tomography are precious imaging techniques as well. They are more expensive but bring valuable information when used in adequate situations.

Open access
Multiple Use Confidence Intervals for a Univariate Statistical Calibration

Abstract

The statistical calibration problem treated here consists of constructing the interval estimates for future unobserved values of a univariate explanatory variable corresponding to an unlimited number of future observations of a univariate response variable. An interval estimate is to be computed for a value x of an explanatory variable after observing a response Yx by using the same calibration data from a single calibration experiment, and it is called the multiple use confidence interval. It is assumed that the normally distributed response variable Yx is related to the explanatory variable x through a linear regression model, a polynomial regression is probably the most frequently used model in industrial applications. Construction of multiple use confidence intervals (MUCI’s) by inverting the tolerance band for a linear regression has been considered by many authors, but the resultant MUCI’s are conservative. A new method for determining MUCI’s is suggested straightforward from their marginal property assuming a distribution of the explanatory variable. Using simulations, we show that the suggested MUCI’s satisfy the coverage probability requirements of MUCI’s quite well and they are narrower than previously published. The practical implementation of the proposed MUCI’s is illustrated in detail on an example.

Open access