SIMULATION OF A CLOSED SYSTEM OF A DC ELECTRIC DRIVE WITH A WIDTH-PULSE CONVERTER

This article investigates the regulation of the angular speed of an electric drive (ED) with a pulse-width converter (PWC) and a direct current motor (DC motor) of independent excitation (NV) when controlled in a closed-loop system. A proportional-integral (PI) -regulator was used as a regulator of the angular velocity. To analyze the processes in the closed-loop SHIP-DPT system, the methods of simulation are used. The principle of operation of an electric drive with control from a PWM is described. Developed and modeled EP circuits with PWM in the Matlab environment using blocks from the Simulink / SimPowerSystem library. A model block has been modeled that calculates the static and dynamic power losses of the PWP IGBT. To calculate the static and dynamic losses, the method of approximating the loss graphs was used. The obtained mathematical dependences describe quite accurately the graphs of the power losses of the IGBT transistor. It is shown that when using a PI-controller, the angular speed of the electric drive is set according to a given speed reference signal.

Migration Processes Between Russia and Armenia: Trends and Statistical Accounting Features

The purpose of the article is to characterize the features of statistical accounting of various categories of migrants and to analyze migration processes between the two countries in the context of integration within the EAEU. On the basis of microdata of the Integrated Survey of Household Living Conditions conducted in Armenia, specific characteristics of migration towards Russia are determined, such as: the duration of stay of a migrant worker in another country, forms of employment, income level, the amount of money transfers, etc. The features of statistical accounting of various groups of migrants are revealed, recommendations for improving the methodology of accounting for migrants from the point of view of its unification across the EAEU countries, as well as the inclusion of a model block of migration issues in the census lists of the EAEU countries are considered.

Do Different Models Induce Changes in Mortality Indicators? That Is a Key Question for Extending the Lee-Carter Model

The parametric model introduced by Lee and Carter in 1992 for modeling mortality rates in the USA was a seminal development in forecasting life expectancies and has been widely used since then. Different extensions of this model, using different hypotheses about the data, constraints on the parameters, and appropriate methods have led to improvements in the model’s fit to historical data and the model’s forecasting of the future. This paper’s main objective is to evaluate if differences between models are reflected in different mortality indicators’ forecasts. To this end, nine sets of indicator predictions were generated by crossing three models and three block-bootstrap samples with each of size fifty. Later the predicted mortality indicators were compared using functional ANOVA. Models and block bootstrap procedures are applied to Spanish mortality data. Results show model, block-bootstrap, and interaction effects for all mortality indicators. Although it was not our main objective, it is essential to point out that the sample effect should not be present since they must be realizations of the same population, and therefore the procedure should lead to samples that do not influence the results. Regarding significant model effect, it follows that, although the addition of terms improves the adjustment of probabilities and translates into an effect on mortality indicators, the model’s predictions must be checked in terms of their probabilities and the mortality indicators of interest.

Principle and Model Block Diagrams of Cd Content Monthly Variation in Surface and Bottom Waters in Central Bay

According to survey data, in Jiaozhou Bay in 1992, the vertical distribution of Cd content and monthly changes in the surface and the bottom of the central sea area of Jiaozhou Bay were studied, and monthly changes, migration processes and variational principles of the Cd content in surface and bottom water were determined. In May, August, and October, the water body that the main sea current did not pass through were those in the center of the bay. Cd content in central surface water of Jiaozhou Bay was not transported from any source outside the bay from May to October. The results showed that Cd content transported by the main sea current changed from low to high in October, May and August; Cd content transported by the bay current changed from low to high: October, August and May; Cd content in surface water in the bay center changed from low to high in: August, May and October; Cd content in the bottom bay center changed from low to high in May, October and August. Thus, from May to October, monthly changes in these four parts were different. For this reason, the monthly variation principle of Cd content in the surface and bottom waters of the bay was proposed. In addition, the model block diagrams were established to show the change process and principle of Cd content deposition and migration. The principle shows that the bay current has no direct effect on the surface water in the center of the bay from May to October. However, the bottom water body in the center of Jiaozhou Bay was greatly affected, and the surface water body in the center of Jiaozhou Bay was further affected by the upwelling.

The land surface mildly contaminated by Hg

The Hg content in the waters of Jiaozhou Bay was within 0.010-0.060μg/L in May, September and October 1993, which conforms to the seawater quality standards of Class I and II. It indicates that in the entire waters of Jiaozhou Bay, there were some water areas that did not get contaminated by Hg while some areas got mild contamination by Hg in May, September and October. In May, the variation range of Hg content in the waters of Jiaozhou Bay was 0.010-0.046μg/L. In September, it ranged within 0.007-0.011μg/L. And in October, the content of Hg detected in the waters of Jiaozhou Bay was 0.060μg/L. There were three sources to transport Hg content, open sea currents, Licun river and the surface runoff. The Hg content from the transportation of open sea currents was 0.046μg/L, from the Licun river was 0.011μg/L and from the surface runoff was 0.060μg/L. This paper builds a model block diagram to present the different paths and Hg contents that were input in the Jiaozhou Bay. In May, the open sea currents did not get any contamination of Hg; in August, the Licun river did not get any contamination of Hg as well; while in September, the surface runoff was mildly contaminated by Hg. The author concluded two points about the migration of Hg content: 1) Human activities discharge Hg to the land so that the Hg content could directly run to the ocean through the surface runoff. As the Hg content transported by surface runoff was relatively high, it resulted that the nearshore waters got mild contamination of Hg content. On the other hand, the surface runoff transported Hg to rivers, resulting relatively low content of Hg. Then rivers delivered the Hg content to nearshore waters, leading to a non-contaminated condition of rivers. 2) Human activities input Hg content to the ocean in a long period, resulting the increase of Hg content in the ocean. As the accumulation of Hg content in the ocean, the ocean got close to the mild contamination status.

Persepsi Mahasiswa Terhadap Kinerja Dosen Dalam Pembelajaran Dengan Model Block System Learning

This research is aimed to know students perception concering to lecturer’s performance in block system learning model. Focus and research subject is students informatics managemen study program in LP3I Polytechnic. This research using quantitavie descrivtive method with likert scale survey questionnaire. The results of this research after analyzing questionnaire data from students with the 200 population an take only 67 as respondent after counting using Slovin formula, that we have known: 1) students experience in learning process we got highest mean score 3.92%; 2) learning plan as lecturer prepared before learning process in questionnaire statement “lecturer prepare and and use learning design on semester (RPS) as guidelines for learning implementation proses” was getting highest mean score 3,79%; 3) in implementation learning that have done by lecturer, was getting highest mean score on 4,01% and lowest mean score on 3.26%; 4) in assessment learning, got mean score on 3.65%; 5) in infrastructures, we got highest mean score on 3.82% and lowest mean score on 3.29% from questionnaire statement of “the classroom and the laboratory capacity is support for getting purpose success leaning; 6) the last components is the use of technology in learning we got mean score 3.37%.

Graphic models as a means of visualization text tasks in elementary school

The paper substantiates the use of the method of graphic modeling, as one of the effective means of visualizing the solution of a text problem in accordance with the requirements of the federal state educational standards elementary general educationin the field of the formation of cognitive educational skills among students. Based on the analysis of educational and methodological complexes in mathematics for elementary school, a classification of graphic models used in solving text problems is compiled. The article also provides examples of solving tasks using the compilation of a graphical model "block diagram" and discusses the methodological features of working with a text task on a model of this type.

MANAJEMEN PEMBELAJARAN MODEL BLOCK SYSTEM LEARNING PADA PENDIDIKAN TINGGI VOKASI DI POLITEKNIK LP3I

Penelitian ini bertujuan untuk mengetahui manajemen pembelajaran pada pendidikan tinggi vokasi dengan menggunakan model pembelajaran block system learning. Penelitian ini dilakukan di Politeknik LP3I dengan menggunakan metode penelitian deskriptif kualitatif dan objek penelitian Dosen Polireknik LP3I Bandung. Pengambilan data dilakukan dengan cara melakukan observasi, wawancara, dokumentasi, dan angket. Hasil penelitian diketahui bahwa: 1) pada perencanaan model pembelajaran block system learning, dosen terlibat dalam perancangan kurikulum PT, termasuk silabus dan RPS mata kuliah memperoleh rerata yang paling tinggi sebesar 4,03%; 2) pelaksanaan model pembelajaran block system learning, dosen melaksanakan pembelajaran sesuai dengan tuntutan kurikulum dan kebutuhan kompetensi mahasiswa memperoleh rerata sebesar 3.85%; 3) penilaian dan evaluasi dilakukan dengan cara menentukan prosedur penilaian yang memperoleh rerata sebesar 3,74%, serta Melakukan peniliaian dengan menggunakan tes dalam bentuk teori dan praktikum memperoleh rerata sebesar 4,10%; 4) sebagai faktor pendukung, Institusi memberikan kebebasan dalam pengembangan kurikulum pembelajaran sesuai dengan KKNI dan SKKNI mendapat rerata sebesar 3,65%. Adapun yang menjadi faktor penghambat dalam pembelajaran dengan model block system learning, dosen Mengalami gangguan pada fasilitas yang bersifat software maupun hadware terhadap perencanaan, pelaksanaan, dan evaluasi pembelajaran dengan rerata sebesar 4,00%; 5) Dampak capaian kompetensi mahasiswa sesuai dengan kurikulum PT yang berjalan memperoleh rerata sebesar 3.83%.