$G$-deviations of polygons and their applications in Electric Power Engineering

For any metric space $X$ endowed with the action of a group $G$, and two $n$-gons $\vec x=(x_1,\dots,x_n)\in X^n$ and $\vec y=(y_1,\dots,y_n)\in X^n$ in $X$, we introduce the $G$-deviation $d(G\vec x,\vec y\,)$ of $\vec x$ from $\vec y$ as the distance in $X^n$ from $\vec y$ to the $G$-orbit $G\vec x$ of $\vec x$ in the $n$-th power $X^n$ of $X$. For some groups $G$ of affine transformations of the complex plane, we deduce simple-to-apply formulas for calculating the $G$-deviation between $n$-gons on the complex plane. We apply these formulas for defining new measures of asymmetry of triangles. These new measures can be applied in Electric Power Engineering for evaluating the quality of 3-phase electric power. One of such measures, namely the affine deviation, is espressible via the unbalance degree, which is a standard characteristic of quality of three-phase electric power.

Methods for adaptive control of objects with variable parameters

The work uses the method of standard characteristic polynomials, based on the Lyapunov theorem on adaptive control systems, the theory of flexible and robust control, methods of the theory of nonlinear systems. When modeling an internal combustion engine, methods of identification theory were additionally involved. When obtaining theoretical results, the method of Lyapunov functions, the method of standard characteristic polynomials, methods of the theory of adaptive and robust control, methods of the theory of nonlinear systems were used. When constructing a model of an internal combustion engine, methods of identification theory were additionally involved. For the synthesis of control systems in conditions of uncertainty, one of the topical directions is adaptive systems. These are control systems that compensate for parametric, signal, functional, or structural uncertainties of the control object by automatically adjusting the controller during the system's working operation, i.e., adaptive systems make up for the lack of a priori information about the control object during operational operation. To solve the problem of managing undefined objects, for example, classical methods are used. In such methods, when state variables are immeasurable, it becomes necessary to use additional dynamic filters. Classical methods are more often used for a limited class of objects. In the case of class extension, the structure of the control algorithm becomes more complicated.

The Pathogenesis Characteristics and Symptom of Covid-19 in the Context of Establishing a Nursing Diagnosis

Covid-19 is a disease that causes a global health emergency, caused by SAR-CoV2 and transmitted through droplets. Viruses attached to host cells are strongly bound to ACE2 causing excessive inflammatory reactions (Cytokine Storm). The incubation period 1-14 days, causing signs and symptoms of the respiratory syndrome, fever, leukopenia, thrombocytopenia, and in severe conditions multi-organ failure that ends in death. In May 2020 the world mortality rate increased by 15.45%, which previously was March 2020 at 3.4%. The concept of pathogenesis is needed as an effort to provide understanding in handling Covid-19 so that mortality can be controlled. Tracing and understanding the characteristics of Covid-19 pathogenesis that gives rise to various pathological responses of the body becomes an interesting analytical study to establish an appropriate diagnosis, including nursing diagnoses in order to develop a comprehensive nursing plan. This study aims to review the characteristics of covid-19 pathogenesis in the context of establishing a nursing diagnosis according to the Indonesian Nursing Diagnosis Standards. A literature study is done by analyzing the characteristics of COVID-19 signs and symptoms and comparing the major and minor data groupings that exist in the Indonesian Nursing Diagnosis Standard. Characteristic pathogenesis results from mild, moderate and severe symptoms. Grouping results refer to nursing diagnoses including ineffective airway clearance, ventilator weaning disorders, gas exchange disorders, ineffective breathing patterns, the risk of spontaneous circulatory disorders, hyperthermia and anxiety. Keywords: Nursing diagnosis Covid-19, signs anda symptome covid-19, pathogenesis Covid-19, SAR-CoV2

Optimal Coordination of Overcurrent Relays in Microgrids Considering a Non-Standard Characteristic

The optimal coordination of overcurrent relays (OCRs) has recently become a major challenge owing to the ever-increasing participation of distributed generation (DG) and the multi-looped structure of modern distribution networks (DNs). Furthermore, the changeable operational topologies of microgrids has increased the complexity and computational burden to obtain the optimal settings of OCRs. In this context, classical approaches to OCR coordination might no longer be sufficient to provide a reliable performance of microgrids both in the islanded and grid-connected operational modes. This paper proposes a novel approach for optimal coordination of directional OCRs in microgrids. This approach consists of considering the upper limit of the plug setting multiplier (PSM) as a variable instead of a fixed parameter as usually done in traditional approaches for OCRs coordination. A genetic algorithm (GA) was implemented to optimize the limits of the maximum PSM for the OCRs coordination. Several tests were performed with an IEC microgrid benchmark network considering several operational modes. Results showed the applicability and effectiveness of the proposed approach. A comparison with other studies reported in the specialized literature is provided showing the advantages of the proposed approach.

The Factors that Affect the Effectiveness of Item Bank (Research at the University of Saigon)

Test methods are the key to determining the quality of the training, the teaching capacity of the teacher and the learning competency of the student. To assess the validity the competency of students in each subject, the item bank is an integral part of the training process. The quality of item bank is must ensure that standard characteristic parameters, and the given requirements evaluate the different student's ability. The article research on the factors that affect the effectiveness of item bank at Saigon University through the results of the study and analysis of the information collected from 107 lecturers that participating in the item compiling. The results show that two factors includes the item compiling technique and the motivation of the item compiling participants influences on the effectiveness of item bank positively and strongly.

Checklist of the vascular flora of Wielkopolska (Poland): casual alien species

The list of alien vascular plant species only temporarily occurring in Wielkopolska refers to the previously published list of native and permanently established plants. Together, these two lists document the vascular flora of this region at the beginning of the 21st century. The current list, like the previous one, is a result of critical analysis of both contemporary and historical data, collected since the beginning of the 19th century. All information accessible in herbarium collections, publications and unpublished materials was used. A critical analysis was conducted at the taxonomic, nomenclatural, chorological and habitat levels, based on the verification of negative information not supported by sufficient arguments. The list is presented in an alphabetical order. Information on each species includes: family affinity, life form, geographic and historic status. In cases particularly disputable, the standard characteristic of a species was supplemented with an additional commentary.

The contact property for symplectic magnetic fields on

In this paper we give some positive and negative results about the contact property for the energy levels ${\rm\Sigma}_{c}$ of a symplectic magnetic field on $S^{2}$. In the first part we focus on the case of the area form on a surface of revolution. We state a sufficient condition for an energy level to be of contact type and give an example where the contact property fails. If the magnetic curvature is positive, the dynamics and the action of invariant measures can be numerically computed. The collected data hint at the conjecture that an energy level of a symplectic magnetic field with positive magnetic curvature should be of contact type. In the second part we show that, for a small energy $c$, there exist a convex hypersurface $N_{c}$ in $\mathbb{C}^{2}$ and a double cover $N_{c}\rightarrow {\rm\Sigma}_{c}$ such that the pull-back of the characteristic distribution on ${\rm\Sigma}_{c}$ is the standard characteristic distribution on $N_{c}$. As a corollary, we prove that there are either two or infinitely many periodic orbits on ${\rm\Sigma}_{c}$. The second alternative holds if there exists a contractible prime periodic orbit.