measuring instruments
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This type of research uses a quantitative approach.  The quantitative approach is the approach used in research by measuring the indicators of the research variables in order to obtain an overview between these variables. Quantitative research is used to examine the population or sample. Data is collected using instruments or measuring instruments, then analyzed statistically or quantitatively. The Universitas 17 Agustus 1945 Surabaya runs the Independent Student Exchange program by accepting 32 inbound students and sending outbound students as many as 167 students throughout Indonesia outside Java, where the archipelago module is a compulsory subject offered by the Ministry of Education and Research and Technology. In this activity, there were several recipient universities that only provided online learning, so students couldn’t directly explore the knowledge gained during the PMM program. However, this doesn’t dampen the enthusiasm of students to continue learning about the diversity that exists in Indonesia.

Abstract Urban agglomerations face the risk of overflowing rivers due to intense urbanization in flood-prone areas and the climate change effects. Despite the important protective measures deployed to reduce the fluvial flooding risk, additional efforts are still needed. This work aims to propose a new complementary non-structural protection measure, used to reduce the river flooding risk. The study is part of the NABRAPOL (NEBRASKA POLYMER) project, which aims to improve knowledge of the drag reduction effect by adding polymers in open-channel flows. The addition of polymers, even in limited concentrations, allows high friction to decrease with the typical Manning coefficient reduced up to 45%. An application case on a real watercourse is presented in this article. Two measurement campaigns are carried out on a river along 30 km. Experimental devices are deployed, and non-intrusive hydraulic measuring instruments are installed at the study field. Surface velocities are evaluated by the Large-Scale Particle Image Velocimetry (LSPIV) technique, and water depth is measured using ultrasonic radar sensors over the river. Measurement results show that the addition of 20 ppm of polymers in the flows results in a marked drag reduction by decreasing the water depth to 18% of its initial depth. The drag reduction technique by addition of small concentrations of polymers can be considered as a new and effective method to reinforce the measures already deployed in the flood risk management strategy since it allows the water depth to be decreased thus avoid overflowing rivers in the extreme flooding event.

The features of the hardware and technological design of the AM-1360 series ammonia synthesis units operating in Ukraine are established, the main of which is the use of heat-using ammonia-water absorption and refrigeration units in the secondary condensation complex. The analysis of the functioning of the absorption and refrigeration units has been carried out. A significant dependence of their efficiency on external disturbances, such as temperature and humidity of atmospheric air, has been established. This causes significant fluctuations in the cooling temperature of the circulating gas in the evaporators of absorption-refrigeration units, which significantly affects the efficiency of ammonia production in general. Based on the results of the analysis of the existing information system, implemented on the basis of the TDC-3000 microprocessor complex, recommendations for its improvement were developed, the presence of which makes it possible to abandon daily analyzes and carry out only control ones to check measuring instruments. Algorithmic support has been developed, implemented in the MATLAB package and tested according to the data of industrial operation of absorption and refrigeration units of the ammonia synthesis unit. This allows the operator, in real production conditions, to obtain operational information on the numerical indicators of the efficiency of operation of absorption and refrigeration units, which characterize their operation to the greatest extent (circulation rate, cooling capacity, circulating gas cooling temperature and thermal coefficient) and make a decision on the possibility of reducing the cooling temperature. of circulation gas in evaporators by changing the frequency of circulation of solutions The created algorithmic software in the MATLAB environment allows embedding a client module, the so-called OPC client. The latter provides technology for free programming of access to current data.

International agreements in the field of metrology and accreditation of calibration laboratories are the basis for establishing global metrological traceability. Important elements of metrological traceability are calibration of measurement standards and measuring instruments, assessment of measurement uncertainty. The International Laboratory Accreditation Cooperation has a specific policy regarding on traceability of measurement results and estimation of measurement uncertainty in calibration. The partial concept diagram around metrological traceability in accordance with the International Vocabulary of Metrology is proposed. This diagram contains a total of nine metrological concepts, which have most of the associative relations. There are associative relations between the concept of metrological traceability chain and concepts of metrological traceability, measurement standard, calibration and calibration hierarchy, and through the concept of measurement standard with the concept of measurement uncertainty. Systems thinking to the analysis of state of proposed terminological system around metrological traceability was applied. For construction of generalized metrological traceability chain, all the established properties of the system elements around the terminology system of metrological traceability were taken into account. Generalized metrological traceability chain for different levels of the calibration hierarchy was proposed. The proposed chain can be used to develop appropriate chains for specific areas of measurement. To achieve this, it is necessary to determine the specific measured value, the required measurement uncertainty for different levels of the calibration hierarchy and select the necessary measurement standards. Such schemes should be used in national metrology institutes and calibration laboratories.

Recently, there has been a revival of interest in the use of the information approach in the theory of measurements. Unlike the traditional approach, information theory does not evaluate error or uncertainty, but entropy and the amount of information. This article analyzes a number of recent publications that develop ideas for the information approach. The limitations and disadvantages of both the entropy approach and the concept of uncertainty are indicated. As a compromise solution, it is proposed to use a criterion based on the Bongard’s uncertainty and useful information. The concept of information uncertainty is proposed, which is estimated by the amount of negative useful information, that is, misinformation introduced by the measuring instrument. Some methods for calculating information uncertainty are described. The problems of using the uncertainty approach are noted. This approach does not imply the use of such a generalized characteristic of measuring instruments as an accuracy class. The article proposes an analogue of the accuracy class in the form of relative informational uncertainty, expressed as a percentage. This will make it possible to evaluate the quality of the measuring instrument by a single parameter, the calculation of which requires a minimum of computational operations.

Abstract: Work accidents that occur in the workplace 24 percent are caused by the environment or equipment that is not up to standard. The physically affecting environment of work space, lighting, air temperature in the workplace, color of the workspace, cleanliness, and also the media used to provide entertainment to workers. PT X Singosari is one of the PTs that produces iron reinforced concrete by using work tools in the form of machines and materials needed in accordance with production needs. This type of research is a qualitative study with observational descriptive design. The research instruments are environmental health measuring instruments and observation sheets. Data collection techniques by way of interviews, observations, and also measuring the conditions of the work environment. The final result of the study showed that the results of the unmet observations by the different levels of the operating are include 11 sub-indicators, the mixer work area 10 sub-indicators, the printing work area 10 sub-indicators, the loading work area 4 sub-indicators, and the concrete checking laboratory area 8 sub-indicators. The results of measuring the intensity of lighting in the iron, printing and loading work areas are up to standard, while the mixer and laboratory work areas are not up to standard. The temperature in the concrete and checking laboratory area is up to standard, while the temperature in iron, mixer, printing and loading is not up to standard. Noise in the iron work area, printing, loading and concrete checking laboratory is in accordance with the standard, while the mixer work area is not up to standard. Abstrak: Kecelakaan kerja yang terjadi di tempat kerja 24 persen disebabkan oleh lingkungan atau peralatan yang tidak sesuai standar. Lingkungan secara fisik yang mempengaruhi kinerja yaitu ruangan kerja, penerangan, kebisingan, suhu udara di tempat kerja, warna ruangan kerja, kebersihan, dan juga media yang digunakan untuk memberikan hiburan kepada pekerja. PT X Singosari merupakan salah satu PT yang melakukan produksi beton bertulang besi dengan menggunakan alat kerja berupa mesin dan material yang dibutuhkan sesuai dengan kebutuhan produksi. Jenis penelitian ini adalah penelitian kualitatif dengan desain deskriptif observasional. Instrumen penelitian yaitu alat ukur environmental health dan lembar observasi. Teknik pengumpulan data yaitu dengan cara wawancara, observasi, dan juga pengukuran kondisi lingkungan kerja. Hasil akhir dari penelitian didapatkan hasil observasi yang belum terpenuhi dengan jumlah berbeda yaitu Area kerja pembesian terdapat 11 sub indikator, area kerja mixer 10 sub indikator, area kerja pencetakan 10 sub indikator, area kerja pemuatan 4 sub indikator, dan area laboratorium pengecekan beton 8 sub indikator. Hasil pengukuran intensitas pencahayaan di area kerja pembesian, pencetakan dan pemuatan sudah sesuai standar sedangkan area kerja mixer dan laboratorium belum sesuai standar. Suhu di area laboratorium pengecekan beton sudah sesuai standar sedangkan suhu di pembesian, mixer, pencetakan dan pemuatan belum sesuai standar. Kebisingan di area kerja pembesian, pencetakan, pemuatan dan laboratorium pengecekan beton sudah sesuai dengan standar sedangkan area kerja mixer belum sesuai standar.

Introduction. This paper investigates a transmission system based on FBMC/OQAM multiplexing. This system is characterized by a high spectral efficiency, thereby attracting interest as an alternative transmission method in future wireless mobile communication standards. However, a disadvantage of the system is the high complexity of signal processing. There are numerous publications that study the FBMC/OQAM system from a theoretical perspective. This paper presents an experimental study of a transmission system based on FBMC/OQAM.Aim. Verification of a transmission system based on FBMC/OQAM multiplexing in a wireless channel.Materials and methods. Computer simulation modeling in Matlab and experimental research using Keysight and Rohde & Schwarz certified measuring instruments.Results. A model of synthesis and signal processing was developed, and a frame structure was proposed. The processing included synchronization, since the study was carried out in a wireless double-dispersive channel. Time synchronization was provided by the method of time-domain correlation. A preamble consisting of two symbols was used for CFO compensation. Channel estimation in FBMC/OQAM was conducted by pilot symbols spread over the time-frequency domain, a method with an auxiliary pilot to compensate for intrinsic interference, as well as Zero Forcing and a linear interpolator. As a result, dependences of the bit error rate on the Eb/N0 in various channels were obtained. An error rate of 10−4 was achieved under the Eb/N0 equal to 13.4 dB, 15.3 dB and 20.9 dB in the first, second and third channel, respectively.Conclusion. A FBMC/OQAM-based transmission system with a linear equalizer can operate without a cyclic prefix in a multipath wireless channel, providing comparable noise immunity to OFDM-CP. Long frames should be used to obtain greater spectral efficiency, due to the presence of a transition zone at the beginning and end of the FBMC/OQAM frame.