scholarly journals CRITERIA AND METHODOLOGY OF COMPLEX EVALUATION OF BITUMINOUS CONCRETE MIXER QUALITY/ASFALTBETONIO MAIŠYTUVO KOKYBĖS KOMPLEKSINIO VERTINIMO KRITERIJAI IR METODIKA

2001 ◽  
Vol 7 (3) ◽  
pp. 213-223
Author(s):  
Henrikas Sivilevičius
Keyword(s):  
Mathematical Model ◽  
Concrete Mixture ◽  
Significance Level ◽  
Environmental Care ◽  
Expert Opinions ◽  
Complex Evaluation ◽  
Concrete Mixer ◽  
Care Economy ◽  
Bituminous Concrete

The structure and sequence of technological operations of mixers for bituminous concrete mixtures, functioning in Lithuanian bituminous concrete mixing plants have been analyzed. The problems, which are subject to interest by the owners of bituminous concrete mixers, have been systematized. The necessity and objectives of quality evaluation of the functioning bituminous concrete mixers have been proved. A new multi-criteria mathematical model for determining quality of bituminous concrete—consisting of the sum of 4 group indicators, which evaluate quality of bituminous concrete mixture production in the mixer, environmental care, economy and technological universality—has been provided. The following 9 criteria make up the mathematical model, which can be used for calculation of quality indicator K of the working bituminous concrete mixer: accuracy of the bituminous concrete mixture content, produced in the mixer, ie the conformity of its component quantity with the project requirements (s); its temperature conformity with the temperature determined (t); its homogeneity in the batch, described by the mixing quality of batched components (h); environmental care, when the air is polluted by pollutants, thrown out from bituminous concrete (aa); bituminous concrete mixture production expenses as for one ton of (gi); level of physical and moral wear of the mixer (nl); expenses, needed for its maintenance and reconstruction (rr); use of its capacity when producing bituminous concrete mixture (pn); as well as technological universality of bituminous concrete mixer, ie ability to produce mixtures of different types and marks (tu). Coefficients of significance (importance) of all criteria are determined, using expert research methods. For this purpose a questionnaire for respondents (experts) has been prepared, which was filled by 43 scientists and production specialists, who have good knowledge of technology of bituminous concrete mixture production. The high value of concordation coefficient (W = 0,719) has shown good coordination of expert opinions, because X 2 = 247,5 is much higher than critical X 2 kr value with ε = 8 freedom level and 1% of accepted significance level, which makes up only 20,09. The experts believe that the most important criteria, reflecting the quality of bituminous concrete mixture are S([Xbar] j = 8,60), H([Xbar] j = 7,58), t(Xj = 7,3o), following in the range is the criterion AA (Xmac;j = 4,95), TU([Xbar]j = 4,56), GI([Xbar]j= 3,91), NL([Xbar]j = 3,47), and at the end least important RR([Xbar]j = 2,44) and PN([Xbar]j = 2,19). total sum of criteria is 45. The bituminous concrete mixer quality change when using it has been provided. The relation of its quality coefficient K reduction rhythm and level of conformity with the requirements imposed and constantly getting stricter has been analyzed.

scholarly journals CONDITIONAL OPTIMIZATION MATHEMATICAL MODEL OF THE ASPHALT CONCRETE MIXTURE GRADING

2002 ◽  
Vol 8 (2) ◽  
pp. 125-132
Author(s):  
Henrikas Sivilevičius ◽  
Valentinas Podviezko
Keyword(s):  
Mathematical Model ◽  
Asphalt Concrete ◽  
Optimization Method ◽  
Concrete Mixture ◽  
Mass Ratio ◽  
First Time ◽  
Model Algorithm ◽  
Purification Equipment ◽  
Conditional Optimization

A new partial conditional optimization method which enables to select the best ratio of imported fillers not only while designing the composition of asphalt concrete mixture but also while adjusting the composition of the produced asphalt concrete mixture according to the actual quality of hot fractions is presented. The constructed mathematical model, algorithm and the solved task prove that irrespective of the number of fillers (from 2 to 7 and more) the ratio of their mass can be selected which enables to produce an asphalt concrete mixture which meets the requirements of the composition project best. The mass ratio λ of imported fillers A 1 and reclaimed dust A 2, which settled and accumulated in the dry purification equipment of an asphalt concrete plant presented in Regulations DAT.AD-96 was taken into account for the first time. Methodological scientific novelty and a possibility to apply it in practice can improve the control of asphalt concrete mixture production.

scholarly journals Application of the method of complex assessment of the quality of high rise apartment buildings in practice

2021 ◽  
Vol 258 ◽  
pp. 09031
Author(s):  
Yana Shesterikova
Keyword(s):  
Mathematical Model ◽  
Desirability Function ◽  
Residential Buildings ◽  
Residential Building ◽  
Building Construction ◽  
High Rise ◽  
Apartment Buildings ◽  
Expert Opinions ◽  
Main Factors

A comprehensive approach to the problem of improving the quality of construction of residential buildings, allows you to take into account various main factors that affect the quality of construction in General. Using the method of expert opinions, the most significant parameters were identified. The weight of each factor is determined using a mathematical model. The experiment examined three levels of variation in significance for each group of factors. After obtaining a discrete value of a complex indicator of the quality of construction of a residential building, it is interpreted using adapted quantitative ranges of values of the generalized Harrington desirability function. A method has been developed to determine the effectiveness of organizational and technological decisions made. An algorithm has also been developed to improve the quality of residential building construction.

scholarly journals THEORETICAL PRINCIPLES AND EXPERIMENTAL DATA TO IDENTIFY STABILITY OF ASPHALT CONCRETE COMPONENTS IN FINALLY DOSED MINERAL MATERIALS

Transport ◽  
2002 ◽  
Vol 17 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Henrikas Sivilevičius
Keyword(s):  
Experimental Data ◽  
Asphalt Concrete ◽  
Concrete Mixture ◽  
Sand Particle ◽  
Regression Equations ◽  
Mineral Component ◽  
Mineral Components ◽  
Concrete Mixer ◽  
Mineral Powder

The duration of asphalt concrete functioning depends on the quality of the asphalt concrete mixture used to pave the road. Grading of hot fractions sieved through technological sieves of asphalt concrete mixture, their pollution with particles of different size as well as stability influence on the quality of an asphalt concrete mixture. Each j - (j = 1...., m) aggregate mineral material or mixture is made up of two (mineral powder, particle of size less than 0,09 or 0,071 mm, and sand, particle of size from 2 to 0,09 mm or 5-0,071 mm) or three (crushed stone, particle size is larger than 2 or 5 mm) mineral components (i = 1, ..., k) . When required technological operations of asphalt concrete mixture production are carried out, the quantity and stability of any i - component in mineral materials change when they move through an asphalt concrete mixer. The more stable the quantity of mineral components in mineral materials (especially in finally dosed) is, the more uniform the composition of asphalt concrete mixture is produced. The experiments showed that when asphalt concrete mixture is produced applying a traditional technology in an asphalt concrete mixer of model D-597, D-508-2A, D-645-3 andD-590, sieved hot fractions of 0–5 mm and 5–15 are polluted with particles of different size by more than 10 per cent; and this pollution is neither uniform nor stable. Following a well-known theory, an average quadratic deviation σ of arithmetic undersized particles sieved through laboratory sieves ~aggregate mineral materials is the greatest when their mean X makes up 50 per cent; therefore, hot fractions of 0–5 mm and 5–15 mm were produced on the experimental data obtained from production as well as regression equations σ = ƒ( X )of statistical indeces of cold mineral powder. The values of average quadratic deviations σ µij of mineral component quantities in those finally dosed mineral materials are obtained from curves drawn according to the regression equations. They can be used to estimate dispersion σ2 Gi of mineral component i in asphalt concrete mixture which depends on the accuracy and stability of technological factors of an asphalt concrete mixer.

The first experience of bipolar transurethral operations in surgery of benign prostatic hyperplasia

2018 ◽  
pp. 10-20
Author(s):  
Н.А. Глотов ◽  
Н.Е. Соколов ◽  
Ю.Б. Смоляков
Keyword(s):  
Benign Prostatic Hyperplasia ◽  
Prostatic Hyperplasia ◽  
Medium Term ◽  
Significance Level ◽  
The Road ◽  
Surgical Methods ◽  
The Comparative Study ◽  
Endoscopic Methods ◽  
Qualitative Characteristics

Представлены результаты внедрения в хирургическую практику урологического отделения Дорожной клинической больницы г. Ярославль биполярной техники трансуретральной резекции (БТУР) и энуклеации простаты (ТУЭБ) для лечения доброкачественной гиперплазии предстательной железы (ДГПЖ) средних и больших размеров. В сравнительное исследование включено 164 пациента, разделенных по методам операции на 2 основные группы (ТУЭБ - 33 человека, БТУР - 49) и 2 контрольные (открытая простатэктомия - ОПЭ - 38 и монополярная ТУР - 44). Для новых эндоскопических методов установлено значимое снижение объема кровопотери, частоты геморрагических осложнений, сроков послеоперационной катетеризации и госпитализации. Для количественной оценки различий средних и относительных показателей использо-вали непараметрический критерий Манна-Уитни, оценка качественных признаков проводилась с применением критерия Пирсона (χ2), уровень значимости различий для исследования выбран р ≤ 0,05. Анализ послеоперационной динамики клинических показателей в среднесрочной перспективе показал сходную радикальность и эффектив-ность сравниваемых методов. Установленные меньшая инвазивность, большая безопасность и лучшая переносимость биполярных эндоскопических операций демонстрируют перспективность их внедрения взамен бывших стандартных хирургических методов, что позволит повысить качество оперативного лечения и сократить затраты стационара. The results of the introduction into surgical practice of the urological Department of the road clinical hospital of Yaroslavl bipolar technique of transurethral resection (BTTR) and enucleation of the prostate (EOTP) for the treatment of benign prostatic hyperplasia (BPH) of medium and large sizes are presented. The comparative study included 164 patients, divided by the methods of surgery into 2 main groups (EOTP - 33 people, BTTR - 49) and 2 control (open prostatectomy - OPE - 38 and monopolar TTR - 44). For new endoscopic methods, a significant reduction in the volume of blood loss, the frequency of hemorrhagic complications, the timing of postoperative catheterization and hospitalization was established. Nonparametric Mann-Whitney test was used to quantify the differences in mean and relative indicators, qualitative characteristics were evaluated using Pearson test (χ2), the significance level of the differences for the study was chosen p ≤ 0.05. Analysis of postoperative dynamics of clinical parameters in the medium term showed similar radicality and effectiveness of the compared methods. The lower invasiveness, greater safety and better tolerability of bipolar endoscopic operations demonstrate the prospects of their implementation instead of the former standard surgical methods, which will improve the quality of surgical treatment and reduce the costs of the hospital.

Проблемы оценки качества при проектировании транспортных услуг

2020 ◽  
pp. 30-40
Author(s):  
S.U. Lyapina ◽  
◽  
V.N. Tarasova ◽  
V.B. Ruchkin ◽  
E.O. Koscheeva ◽  
...  
Keyword(s):  
Life Cycle ◽  
Business Processes ◽  
Service Industries ◽  
Service Organizations ◽  
Quality Of Services ◽  
Market Failures ◽  
Expert Opinions ◽  
Service Life Cycle ◽  
Quantitative Indicators

The quality issues of new services directly affect the competitiveness of service organizations. However, the introduction of new services to the market is often limited only to the construction of the logistics of business processes, and the design applies only to technological equipment and infrastructure, the quality of which ultimately does not always ensure the quality of the services provided. At the same time, quality management affects mainly operational aspects, that is, it covers the later stages of the service life cycle. In resource-intensive service industries (for example, transport, communications, etc.), the high cost of equipment and infrastructure reduces the possibility of changes in service delivery technologies to improve their quality, which leads to inefficiency and market failures due to the fact that the new service does not match the real needs of customers. Despite this, forecasting and planning the quality of a service at the stage «making a decision» to launch a new service on the market remains largely without sufficient attention. The authors prove the need to design the quality of services at the stage «making a decision» to bring new services to the market. The purpose of the article is to describe the approach developed by the authors to assessing the quality of projected services at the early stages of their life cycle, which makes it possible to integrate qualitative and quantitative indicators of the future service and take into account the forecast requests of customers. The proposed approach has two features: (1) forecasting customer requirements for the quality of services is based on the results of machine learning based on data on existing and potential customers, as well as on the basis of the accumulated knowledge base of customer experience and expert opinions; (2) multi-criteria optimization is used, while some of the optimized parameters are discrete and high-quality. In conclusion, the authors demonstrated the advantages of the developed model on the examples of transport and logistics business in the field of passenger and freight transportation in Russia.

Multifactor mathematical model of criticality of welding process of products from aluminum- magnesium alloys

2020 ◽  
pp. 12-18
Author(s):  
F.A. Urazbahtin ◽  
A.YU. Urazbahtina
Keyword(s):  
Mathematical Model ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Welding Process ◽  
Welding Equipment ◽  
Equipment Operation ◽  
Aluminum Magnesium Alloys ◽  
Aluminum Magnesium Alloy ◽  
Welding Materials

A multifactor mathematical model of the welding process of products from aluminum-magnesium alloys, consisting of 71 indicators that assess the quality of the weld, the welding process, costs, equipment operation and quality of the welded material. The model can be used to control and optimize the welding process of products from aluminum-magnesium alloys. Keywords welding, products, aluminum-magnesium alloy, indicators, process parameters, welding equipment, welding materials, electrode sharpening, lining [email protected]

Network analysis models – the secret for success

2004 ◽  
Vol 4 (5-6) ◽  
pp. 383-388
Author(s):  
D.M. Rogers
Keyword(s):  
Mathematical Model ◽  
Field Data ◽  
Essential Element ◽  
Distribution Networks ◽  
Automatic Calibration ◽  
Supply And Distribution ◽  
The World ◽  
Optimum Approach ◽  
Analysis Models

Water is a fundamental necessity of life. Yet water supply and distribution networks the world over are old and lacking in adequate maintenance. Consequently they often leak as much water as they deliver and provide an unacceptable quality of service to the customer. In certain parts of the world, water is available only for a few hours of the day. The solution is to build a mathematical model to simulate the operation of the real network in all of its key elements and apply it to optimise its operation. To be of value, the results of the model must be compared with field data. This process is known as calibration and is an essential element in the construction of an accurate model. This paper outlines the optimum approach to building and calibrating a mathematical model and how it can be applied to automatic calibration systems.

Numerical Simulation on Mold Electromagnetic Eccentric Stirring and Central Segregation of Round Bloom

2013 ◽  
Vol 652-654 ◽  
pp. 2450-2454
Author(s):  
Zhi Hong Zhang ◽  
Guo Guang Cheng
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Electromagnetic Stirring ◽  
Center Line ◽  
Central Segregation

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.

scholarly journals Quality of Life and Associated Factors in Young Workers

2021 ◽  
Vol 18 (4) ◽  
pp. 2153
Author(s):  
José Andrade Louzado ◽  
Matheus Lopes Cortes ◽  
Márcio Galvão Oliveira ◽  
Vanessa Moraes Bezerra ◽  
Sóstenes Mistro ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Odds Ratio ◽  
Cross Sectional Study ◽  
Young Workers ◽  
Cross Sectional ◽  
Physically Active ◽  
Significance Level ◽  
Self Rated Health ◽  
Assess Quality

Background: This study aimed to identify the factors associated with the quality of life of young workers of a Social Work of Industry Unit. Methods: This was a cross-sectional study conducted on 1270 workers. Data were collected using a digital questionnaire built on the KoBoToolbox platform that included the EUROHIS-QOL eight-item index to assess quality of life. Demographic, socioeconomic, behavioral, and clinical variables were considered explanatory. The associations were analyzed using the ordinal logistic regression model at a 5% significance level. Results: Men and women had a mean quality of life of 31.1 and 29.4, respectively. Workers that rated their health as “very good” had an odds ratio of 7.4 (95% confidence interval (CI) = 5.17–10.81), and those who rated it as “good” had an odds ratio of 2.9 (95% CI = 2.31–3.77). Both these groups of workers were more likely to have higher levels of quality of life as compared to workers with “regular”, “poor”, or “very poor” self-rated health. Physically active individuals were 30% more likely to have higher levels of quality of life (odds ratio = 1.3; 95% CI = 1.08–1.65). After adjusting the model by gender, age group, marital status, socioeconomic class, self-rated health, nutritional status, and risky alcohol consumption, the odds ratio of active individuals remained stable (odds ratio = 1.3; 95% CI = 1.05–1.66). Conclusions: In the present study, self-rated health, physical activity, and gender were associated with young workers’ quality of life.

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