Operations Research, Systems Engineering and Industrial Engineering Commons^™

Assessments Of The Application Of Earned Value Management System For Construction Project Performance Measurement In Zanzibar, Juma M. Matindana

Tanzania Journal of Engineering and Technology (TJET)

Many construction projects in developing countries including in Zanzibar suffer from time and budget overruns. The Revolution Government of Zanzibar established different bodies such as Zanzibar Contractors Registration Board (ZCRB), Zanzibar Architects, Engineers and Quantity Surveyors Registration Board (ZAEQRB), Zanzibar Public Procurement and Disposal of Public Asset Authority (ZPPDA), among others with the aim of controlling the performance of project. Often scope creep, time and cost overruns are very common problems in construction projects. This study aims at addressing those problems by assessing the use of Earned Value Management (EVM) methodology in measuring construction industry performance in Zanzibar. The study …

Review On Modifications Of Sisal Fibers For Textile Applications, Liberato V Haule

Tanzania Journal of Engineering and Technology (TJET)

Properties of sisal fibers such as high coarseness and poor drapability made the fibers less suitable in production of conventional textiles compared to synthetic fibers. The environmental consciousness and depletion of petrochemical resources have attracted researchers on investigating the use of natural fibers in the industrial production of conventional textiles. Sisal is among highly researched natural fibers due to its features such as strength, recyclability, availability, low processing cost, light weight and ease process ability. This paper reviews possible modifications of sisal fibers to enhance performance in conventional textiles applications

Modeling And Dynamic Correction Of The Thermal Radiation Fluxes Measuring System, Olexander Alekseevich Sytnik, Fatima Mirazizovna Sagatova

Chemical Technology, Control and Management

Temperature measurements are currently an integral part of modern production, in particular, energy, aviation, instrumentation, etc. Therefore, the need to improve the accuracy of measurement, control and regulation of temperature largely determines the technical and economic efficiency of production. The development of reliable methods for temperature control under various conditions and the creation of specific devices is one of the most important tasks of modern instrumentation. The article deals with the issues of solving the problems of modeling and correcting the dynamic characteristics of a system for measuring thermal radiation fluxes using the integral method of signal recovery. For computer …

Topological Interpolation Method For Modeling Dynamic Systems, Isamiddin Xakimovich Siddikov, Dilnoza Maxamadjanovna Umurzakova

Chemical Technology, Control and Management

The method of simulation structural-complex continuous-discrete control systems is discussed. For simulation and calculation of dynamic processes in continuous-discrete systems topological interpolation method is proposed, based on application of hybrid methods of space of state variables and interpolation of signals. The essence of the method is that the dynamics of the investigated system, considered at the final interval, is broken down into subintervals, on each of which the processes are described by linear ordinary system differential equations. The computational efficiency of the proposed method was evaluated by comparison with standard methods such as the Runge-Kutta-Merson method. The use of this …

Prediction Using Fire Data Based On Machine Learning Algorithms, Oybek Zokirovich Koraboshev

Chemical Technology, Control and Management

In this article, the process of real-time prediction of the dynamics of fire development in non-stationary and gas-fired areas is carried out by developing a real-time prediction method based on artificial intelligence and deep machine learning (Deep Machine Learning) algorithms. The most commonly used KNN algorithm, CVM algorithm, Random Forest algorithm and Naive Bayes algorithm were used for prediction fire situations.

Investigation Of Magnetic Circuits Of Differential Transformer Displacement Sensors, Sulton Fayzullaevich Amirov, Absaid Khurramovich Sulliev, Shukhrat Azamatovich Sharapov

Chemical Technology, Control and Management

The article examines the magnetic circuits of both existing and developed differential transformer displacement sensors for large linear displacements. These circuits are characterized by a specific distribution structure of magnetic resistance parameters in long ferromagnetic cores and the magnetic capacitance between them. It is shown that in the existing sensor, the distribution of working magnetic flux along the length of the ferromagnetic cores has a nonlinear nature, resulting in a nonlinear relationship between the output signal in the form of electromotive force and the input linear displacement of the sensor. It has been established that by selecting the law of …

Intellectualization Of The Process Of Monitoring Of Complex Technological Productions, Dmitry Semenovich Karpovich, Umidjon Abdimajitovich Ruziev

Chemical Technology, Control and Management

The article deals with the creation of intelligent monitoring systems for complex technological processes. The methods and models of the intellectualization of information processing systems are analyzed. The advantages of using intelligent measuring instruments in monitoring systems are given, which allow obtaining reliable information necessary for the effective control of complex technological processes. The issues of using intelligent measuring instruments in monitoring systems are considered. A block diagram of intelligent monitoring of signal processing of complex production processes has been proposed. An algorithm for parametric correction of intelligent measuring instruments in monitoring systems has been developed. A model of a …

Synergetic Synthesis Of Multivariate Nonlinear Dynamic Objects, Isamiddin Siddikov, Komil Usmanov

Chemical Technology, Control and Management

Based on the synergetic approach, the article solves the problem of analyzing a chemical reactor as a control object and formulates recommendations on the structural and topological synthesis of various control system options. The main feature of technological control objects, in which, as a result of hydromechanical, physical, chemical influences on the flows of the starting substances, their physical properties, state of aggregation and composition change, is their multidimensionality, nonlinearity, multiconnectedness, as well as parametric uncertainty of the mathematical model at the design stage. This type of facility includes a chemical reactor, thermal management, which in most cases is carried …

Methods And Algorithms For Monitoring And Prediction Of Various Fire Hazardous Situations, Mizaakbar Xakkulmirzayevich Hudayberdiyev, Oybek Zokirovich Koraboshev

Chemical Technology, Control and Management

This article analyzes emergency situations arising from natural disasters (fires, explosions, earthquakes, floods, landslides, etc.) and man-made accidents. The event in which the values of fire risks in the area decrease uniformly and at the same time the amount of fire risks is minimal is considered optimal. Models, methods, and logistic regression algorithm have been used to predict fire hazard situations and identify potential fire safety measures.

Remote Alignment Fixing Device With Vizir Marks In Base Lcd Indicator, Nodirbek Rustambekovich Yusupbekov, Zahidov Muratovich Nematjon

Chemical Technology, Control and Management

The article substantiates the needs to increase the level of automation of methods and geodetic support of geometric parameters during the construction of buildings and structures. In particular, the method of alignment measurements is considered. This is widely used in determining deviations from the straightness and alignment of the installation of elements in engineering building structures, including hydraulic structures, as well as in the control of process equipment installations, rolling mills, conveyor lines, crane tracks, when monitoring precipitation. and deformations of techno objects. One of the methods of alignment measurements with the use of a visual-optical device – aliniometer and …

The Magnetic Chain Mathematical Models Of A New Angular Displacement Converter With A Variable Active Area Of A Movable Core, Sultan Faizullayevich Аmirov, Ulugbek Shukhratovich Mamadaliyev, Islom Azim Ugli Karimov

Chemical Technology, Control and Management

The article develops mathematical models of the magnetic chain of new differential type angular displacement transformer converter with a variable active area of the movable core, in which the width of the movable ferromagnetic core is a function of the angular displacement of the converter. In this case, the magnetic chain of the converter, divided into three characteristic (before the mobile ferromagnetic core, ferromagnetic core and after the ferromagnetic core) sections, is considered as a magnetic chain with distributed parameters. It is established that when the magnetic resistance of the magnetic chain steel part is not taken into account, the …

Synthesis Methods And Algorithms For Expanding The Dynamic Range Of The Adc, Jumaev Odil Abdujalilovich, Rashidov G'Olibjon Xayriddinovich

Chemical Technology, Control and Management

The modern development of new technologies, in particular, the intensive use of programmable logic integrated circuits in digital information processing tasks, allows for algorithmically and programmatically solving problems, opens up real opportunities to increase accuracy and ensure the required signal conversion speed, and also, it will be possible to take into account the effects of noise and their elimination over the entire time interval band. The article discusses the main methods of digital information processing, analyzes the ways and possibilities of expanding the dynamic range of analog-to-digital converters, as well as the synthesis of appropriate conversion devices, primarily digital filters.

Mathematical Description Of A Bleach Impregnation Reservoir, Bekobod Ibragimov

Chemical Technology, Control and Management

This article discusses the issues of constructing a mathematical model of the technological process of bleaching textile materials in an impregnating reservoir using the heat balance equation, on the basis of which a qualitative analysis of the dynamic properties of an object has been carried out in order to create highly efficient control systems with the use of energy-saving technologies. While constructing a mathematical model characterizing the established and non-established modes of the control object (impregnating reservoir) used changes in heat flow and mass velocity of the incoming tissue. An algorithm for constructing a mathematical model of the process of …

Mathematical Description And Algorithm For Solving The Model Of The Ionite Regeneration Process In The Ion Exchange Method Of Water Softening, Djalolitdin Paxritdinovich Mukhitdinov, Nilufar Abdusami Qizi Yunusova

Chemical Technology, Control and Management

Based on the modern representation of the water softening process by the ion exchange method, modeling was carried out, an algorithm was developed and the ionite regeneration process was calculated in a water softening plant with a fixed ionite layer. To solve the system of equations of the model, special, but simple enough for use in engineering calculations, techniques and methods have been developed and applied. The constructed model and its solution algorithm can be used to predict the process of ionite regeneration in an ion exchange apparatus. It can also be used to calculate the time of the ionite …

Modeling And Adjustment Of A Fuzzy Controller In A Bioreactor Control System, Mahmudov Giyosjon Baqoyevich

Chemical Technology, Control and Management

The article describes the modeling and configuration of a fuzzy controller for the control system of the bacterial oxidation of hard-to-enrich gold-bearing sulfide ores. The simulated logical fuzzy controller allows you to save the consumption of refrigerant water consumed in the process by 4,3%, using it to control the process of bacterial oxidation.

Synchronization Of The Training Of Specialists In The Automation Of Technological Processes In Accordance With The Dynamics Of The Taxonomy Of Learning Goals, Yusuf Shodievich Avazov, Kamola Abdullaeva

Chemical Technology, Control and Management

Changes in the characteristics of modern ones, reflecting them as the "digital generation", inevitably necessitate electronic interactive, mobile and mixed, machine learning, especially in the field of automation and control of technological processes and production. As a consequence of reflecting these realities, there have been parallel changes in the taxonomy of learning objectives - from the classical to the revised rethought and digital.

In order to study the problem of synchronizing the training of future specialists in the field of automation and control of technological processes and production and funny knowledge in accordance with the dynamics of the taxonomy of …

Algorithmic Methods For Developing The Structure Of A Thyristor Electric Drive For Mining Machines, N.R Yusupbekov, O.A. Jumaev, S.S. Turaev

Chemical Technology, Control and Management

The article discusses the creation of algorithmic structures and the development of digital control systems for electric drives of mine-lifting machines, provides some concepts for creating digital control systems using thyristor converters. The analysis of the static volt-ampere characteristics of the thyristor is given, some calculations of the circuits and circuits of the thyristor converter (TP) corresponding to the different modes of operation of the TP are given, and also, based on the synthesis of the dynamic properties and characteristics of the thyristor, an algorithmic structure of the model of the thyristor converter is proposed.

Research Of Three-Phases Current’S Transducers Of Filter-Compensation Devices For Control Reactive Power’S Consumption Of Asynchronous Motor, Ilkhomjon Khakimovich Siddikov, Dilyorbek Karimjonov Doniyorbek O'G'Li -, Abdumutal Abdikarimovich Abdigapirov

Chemical Technology, Control and Management

In the article given materials of developing of three-phase electromagnetic current transducers of reactive power, using with asynchronous motor, methods connecting of two sensing element, series, parallel and differential and loops suitable for each phase, dynamic characteristics of output signals of three-phase electromagnetic current transducers asynchronous motor.

On the basis of modern calculation and design complexes are of great importance in the research variable sizes of three-phase current electromagnetic transducers of filter-compensation devices of reactive power of asynchronous motors. Presented mathematical model of research of electrical, electromagnetic and magnetic elements of electromagnetic current transducers in the …

Modeling Of The Process Of Measuring Conversion Of The Flow Of Liquid And Gaseous Media By The Method Of Variable Pressure Drop, Shukhrat Manapovich Gulyamov, Elbek Elmirza O'G'Li Ortiqov

Chemical Technology, Control and Management

On the basis of material and heat balances, taking into account the initial and boundary conditions, a mathematical model of the process of measuring the transformation of liquid and gaseous technological media by the method of variable pressure drop is constructed. The analysis of the results of studying the influence of non-stationary flows of a controlled medium on the uncertainty of the results of measuring the flow rate of liquids and gaseous mixtures with a changing hydrodynamic structure of the flow of a controlled medium is performed. A comparative analysis of the calculated and experimental transient processes in the measuring …

Virtual Potassium Chloride Analyzer In The System Of Advanced Control Of Potash Fertilizer Production Processes, Umidjon Ruziev, Jahongir Sherboyevich Bekqulov

Chemical Technology, Control and Management

It is proposed to include virtual instrumental quality analyzers of potash fertilizers in the composition of the advanced (advanced) management system. The structure of the virtual analyzer is substantiated using mathematical models of the technological process of drying potassium chloride in its composition. Based on the results of fuzzy clustering, the parameters of the modes of the technological process of drying potassium chloride are determined.

Model For Calculating The Static Characteristics Of Hydraulic Systems Of Hydro Technical Buildings, Mirkhalil Ismailov, Dong Zhang, Farkhod Kasimov

Chemical Technology, Control and Management

Hydraulic mechanisms that actuate flat gates, widely used in hydraulic structures, are studied as hydraulic actuators of the system. Their static mathematical models are developed using an integrated methodology with a hydraulic pump, inlet and suction pipes, and internal and external resistance factors. Unlike existing mathematical models, the model developed in this paper allows a detailed description of the characteristics of hydraulic drives due to the fact that pressure losses in the throttle, regulator, and power amplifier, as well as local resistances in hydraulic pipelines, are taken into account.

Towards Lean Manufacturing In Developing Countries: Research Gaps And Directions In Tanzania, Francis D. Sinkamba

Tanzania Journal of Engineering and Technology (TJET)

In the current knowledge-driven economy, many industries across the globe are forced to adopt manufacturing technologies such as lean manufacturing to remain competitive in the globalized world. Despite the increase in lean manufacturing implementations, the adoption rate in Tanzania is very low and estimated to be 8 percent. Likewise, the sustainability of lean manufacturing tools and practices is still questionable, which shows the need to develop lean maturity models. To date, several lean maturity models have been developed but there is ARTICLE INFO Submitted: July 5, 2022 Revised: Sept. 28, 2022 Presented: Oct. 20, 2022 a lack of maturity models …

Current And Future Trends Of Construction Project Performance Models: A Review, Method Mtana

Tanzania Journal of Engineering and Technology (TJET)

The construction industry (CI) has experienced outstanding growth and contributed to economic growth for many countries, with enormous foreign investments that require quality projects. High pressure to reduce the construction cost and time commonly put the industry at risk of lower quality and safety of the construction facilities. Like many other developing countries, Tanzania needs more stringent quality control measures in the construction sector to contribute positively to sustainable growth. This study thus reviews current and future trends in construction industry performance in Tanzania. The literature review on construction projects (CPs) performance is based on information on time overruns from …

Factors Influencing Total Productive Maintenance Implementation For Thermal Generation Plants, Ismail W. R. Taifa Dr

Tanzania Journal of Engineering and Technology (TJET)

This study accepts that the technical and administrative factors can amplify effective total productive maintenance (TPM) implementation at thermal generation plants. It is noted that there is a limited number of studies that have attempted to understand the subject of TPM implementation in the energy sector. Noting this shortcoming, the authors thought it crucial to generate empirical evidence on the factors influencing effective TPM implementation for thermal generation plants, with evidence from gas-fired plants. A sample of 88 respondents was selected and consulted. Data were collected through questionnaires and analyzed quantitatively by inferential statistics and qualitatively through thematic analysis using …

Towards The Development Of A Framework For Assessing Organizational Governance Maturity For Technical Audit Of Public Works, George Haule

Tanzania Journal of Engineering and Technology (TJET)

The quality of the audit work and its products is often associated with the organizational maturity of the audit function. The absence of a well-defined organizational maturity for an audit function leads to poor quality of audit work or products and ineffective audit function. The lack of a framework for measuring governance maturity was identified as a major deterrent factor to the attainment of quality audit work. Measuring the governance maturity of the technical audit of public works is challenging due to the absence of a maturity framework that fits its needs. The noted shortcomings include: (a) existing maturity frameworks …

Analysis Of Vegetable Oil Refining Technology, Elyor Samadov

Chemical Technology, Control and Management

Innovative technologies for refining vegetable oils are presented, as well as the qualitative characteristics of raw vegetable oils obtained by extraction and mechanical methods. A general review of the chemical composition and impurities of vegetable oils resulting from the reaction between glycerol and fatty acids is carried out, and a brief review of the study to determine the effect of refining on biologically active components.

The analytical review is devoted to a comparative comparison of two types of refining - chemical and physical refining.

Influence Of Magnetomechanical Properties Of Ferromagnetic Materials On The Sensitivity Of A Magnetoelastic Sensor, Sulton Amirov, Kamila Komilovna Jurayeva

Chemical Technology, Control and Management

The requirements of high operational reliability are most fully met by automated monitoring and control systems, the elements of which are magnetoelastic sensors. Such sensors, due to their metrological characteristics, have found application in electrified railway transport, in the metallurgical, metalworking, mining and other industries. The principle of operation of such sensors is based on the fact that in the process of influencing the magnetic core of the sensor by force, there is a change in the magnetic permeability of the material, a change in the magnetic resistance of the circuit, a change in the mutual inductance coefficient of the …

Algorithms For Multi-Factory Polynomial Modeling Of Technological Processes, Farrukh Do'stmirzayevich Jo'rayev, Murodjon Ashurqulovich Ochilov

Chemical Technology, Control and Management

The article reveals the meaning and essence of the modeling method in the study of complex technological processes based on the problematic aspects of building multifactorial relationships and the principles for their elimination. In the case of non-linearity of multifactorial connections of a complex system, the expediency of approximating such functions by polynomials is substantiated. The authors' ideas about the increasing importance of interpolation methods in practice against the background of the possibility of simplification based on the use of modern mathematical hardware and software for integration into the process of modeling and optimizing technological processes due to the complexity …

Structural Model Of The Technological Process Of Storage And Processing Of Oil Raw Materials, N.A Kabulov

Chemical Technology, Control and Management

The technological method of storing and processing oilseed raw materials is structurally modelled in the article. Additionally, it is suggested that the generalized structure be presented as a three-part scheme, consisting of a raw material department, a processing shop, and transportation networks. On the basis of a thorough examination of the characteristics of the constituent parts of the technological complex, a practical model for the problem of the general characteristics of the technological complex is proposed.

Exploring Current And Future Research Trends On Safety Climate In Construction Projects, Kamugisha Joseph Kajumulo

Tanzania Journal of Engineering and Technology (TJET)

Clients, consultants, and contractors in the construction industry can benefit from a safety climate by obtaining knowledge of attitudes and perceptions for better safety outcomes. However, the current and future research trends for safety climate in construction projects have not yet been fully examined. In order to solve this problem, a systematic review of previous research findings using a social network approach must be conducted, and future trends for the safety climate in building projects must be identified. Sixty-three peer reviewed articles were gathered to study the literature on safety climate in construction projects. A social network approach was employed …