scholarly journals Improving the efficiency of machining on metal-cutting machines by aligning the CNC program and the evolutionarily changing cutting dynamics

2021 ◽  
Vol 2131 (5) ◽  
pp. 052027
Author(s):  
V L Zakovorotny ◽  
V E Gvindjiliya
Keyword(s):  
Metal Cutting ◽  
Tool Path ◽  
A Priori ◽  
High Accuracy ◽  
External Control ◽  
Elastic Deformations ◽  
Reduced Costs ◽  
Executive Elements ◽  
Required Quality

Abstract Modern machines with high accuracy provide an accordance of the trajectories of the executive elements to the CNC program. However, this is not guarantee the same accuracy of manufacturing the part. One of the main reasons for the formation of the geometric defects is the elastic deformations of the tool and the workpiece. It is caused by variations of the cutting forces, changes in the rigidity of the workpiece along the tool path. It depends on changes of the properties of the dynamic link formed by cutting. Therefore, there is a problem of synergetic aligning of controlled trajectories with changing cutting properties. In the article, the regularities of the alignment of external control and internal dynamics are considered on the basis of mathematical modeling of the system in which the trajectories of the executive elements are controlled. The case of accounting the a priori given law of changes of the stiffness of the workpiece is considered. The effectiveness of the alignment is estimated by the reduced costs while ensuring the required quality of the parts.

Synergetic approach to improve the efficiency of machining process control on metal-cutting machines

2021 ◽  
Vol 23 (3) ◽  
pp. 84-99
Author(s):  
Vilor Zakovorotny ◽  
◽  
Valery Gvindjiliya ◽  
Keyword(s):  
Dynamic System ◽  
Internal Control ◽  
Metal Cutting ◽  
A Priori ◽  
Machining Process ◽  
External Control ◽  
Processing Efficiency ◽  
Cutting System ◽  
Required Quality

Introduction. The efficiency of processing on metal-cutting machines is evaluated by the reduced cost of producing a batch of parts while ensuring the required quality. In modern production, parts are usually made on CNC machines. Today the CNC program and the trajectories of the machine tool actuators match each other with high accuracy, which, however, does not yet guarantee quality and efficiency of production. The definition of the CNC program is based on the knowledge base of rational modes, tools, coolant and etc. during processing. This base reflects some averaging over the set of machines, tools and processing conditions, and does not take into account changes in the properties of the dynamic system in the process of cutting. Subject. The paper deals with the synergistic matching of external control (CNC programs) and cutting dynamics (internal control). The internal control factors can be set a priori, as well as determined as a result of the influence of irreversible energy transformations in the cutting zone. The purpose of the work is to determine the law of controlling the trajectories of the machine's executive elements in such a way that, with changing properties of the dynamic cutting system, the required surface quality of the part and minimizing the intensity of tool wear are ensured during the processing of the part. Method and methodology. Mathematical simulation of the controlled dynamic system, which properties change due to the a priori set laws of variation of subsystem parameters, as well as changes in the cutting properties conditioned by the power of irreversible energy transformation is presented. Consideration of the power of irreversible energy transformations is necessary for predicting back-edge wear, changes in dynamic coupling parameters, and evolutionary restructuring of cutting dynamics. Results and Discussion. The regularity of matching the CNC program with the changing properties of the cutting process, which allows increasing the processing efficiency while ensuring the required quality of parts, is disclosed. A number of properties of the dynamic cutting system caused by changing trajectory of the longitudinal feed rate of the tool during processing of the shaft, the stiffness change of which is given, are revealed and analyzed.

scholarly journals Synergies in control of the cutting processes

2018 ◽  
Vol 226 ◽  
pp. 02009
Author(s):  
Vilor Zakovorotny ◽  
Valery Gvindjiliya
Keyword(s):  
Metal Cutting ◽  
Dynamic Properties ◽  
External Control ◽  
Metal Cutting Machine ◽  
Process Dynamic ◽  
Cutting Machine ◽  
Processing Control ◽  
Cutting Processes ◽  
Executive Elements ◽  
Dynamic Subsystem

As the rule metal-cutting machine have controllable movements of the executive tool from the computer. However, the shape-generating movements differ from the executive elements movements. These differences are defined by the influence of the deformation of the tool and detail. The deformations are conditioned by complex nonlinear transformation in all system. In turn, the process dynamic system is determined on the basis of the disclosure of the dynamic subsystem interaction. While the dynamic link parameters depend on the trajectories of the executive elements movement. Therefore, it is necessary to agree on the trajectories of the executive elements and the cutting dynamic properties. Agreement characterize the synergies of the external control with the internal links, it characterize the next stage of the enhancement of the cutting processing control.

Construction Control As A Strategy For Improving The Quality Of Buildings And Structures

2020 ◽  
Keyword(s):  
Quality Control ◽  
Life Cycle ◽  
Construction Control ◽  
Construction Sites ◽  
Actual Problem ◽  
Construction Market ◽  
Construction Products ◽  
Underlying Causes ◽  
Required Quality

In construction production, the safety of constructing buildings and structures is achieved by ensuring the required quality as a result of systematic construction control based on the implementation of a complex of technical, economic and organizational measures at all stages of the object's life cycle. The article deals with the actual problem of improving the quality of construction products-buildings and structures in conjunction with the activities of construction control bodies. The article presents the advanced foreign and domestic experience of ensuring the quality control at the construction sites, providing for the prevention of the underlying causes of defects and increasing the interest of the contractors directly. On the basis of the analysis of the current situation with quality control at the construction market, ways to improve its efficiency by developing a unified system of technological implementation of relevant requirements for the quality of construction products, determining the rational number and business load of construction control engineers, as well as the active activities of self-regulatory organizations in this area are offered.

Dynamics of the processes in metal machining

1998 ◽  
Vol 2 ◽  
pp. 115-122
Author(s):  
Donatas Švitra ◽  
Jolanta Janutėnienė
Keyword(s):  
High Frequency ◽  
Machine Tools ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Frequency ◽  
Metal Cutting Machine ◽  
Cutting Machine ◽  
Metal Machining

In the practice of processing of metals by cutting it is necessary to overcome the vibration of the cutting tool, the processed detail and units of the machine tool. These vibrations in many cases are an obstacle to increase the productivity and quality of treatment of details on metal-cutting machine tools. Vibration at cutting of metals is a very diverse phenomenon due to both it’s nature and the form of oscillatory motion. The most general classification of vibrations at cutting is a division them into forced vibration and autovibrations. The most difficult to remove and poorly investigated are the autovibrations, i.e. vibrations arising at the absence of external periodic forces. The autovibrations, stipulated by the process of cutting on metalcutting machine are of two types: the low-frequency autovibrations and high-frequency autovibrations. When the low-frequency autovibration there appear, the cutting process ought to be terminated and the cause of the vibrations eliminated. Otherwise, there is a danger of a break of both machine and tool. In the case of high-frequency vibration the machine operates apparently quiently, but the processed surface feature small-sized roughness. The frequency of autovibrations can reach 5000 Hz and more.

TINGKAT KEAKURATAN DAN KEBERTERIMAAN TERJEMAHAN KALIMAT YANG MENGAKOMODASI TINDAK TUTUR KOMISIF PADA NOVEL INSURGENT (THE ACCURACY AND ACCEPTABILITY OF TRANSLATION ON THE SENTENCES WHICH ACCOMODATE COMMISSIVE SPEECH ACT IN THE INSURGENT NOVEL)

Widyaparwa ◽  
2017 ◽  
Vol 45 (2) ◽  
pp. 151-164
Author(s):  
Novita Sumarlin Putri
Keyword(s):  
Focus Group ◽  
Focus Group Discussion ◽  
Speech Act ◽  
Group Discussion ◽  
Document Analysis ◽  
High Accuracy ◽  
Pragmatic Approach ◽  
Componential Analysis ◽  
Pragmatic Aspects

Tindak tutur komisif merupakan salah satu aspek pragmatik yang harus diperhatikan oleh penerjemah ketika menerjemahkan teks. Hal itu dilakukan agar menghasilkan terjemahan yang berkualitas dari aspek keakuratan dan keberterimaan. Berdasarkan alasan tersebut, penelitian ini bertujuan mendiskripsikan tingkat keakuratan dan keberterimaan terjemahan kalimat yang mengakomodasi tindak tutur komisif dengan pendekatan pragmatik. Data yang digunakan ialah tuturan komisif dan hasil penilaian kualitas terjemahan. Data bersumber dari novel Insurgent karya Veronica Roth dan informan. Data dikumpulkan dengan cara analisis dokumen, kuesioner dan Focus Group Discussion. Selanjutnya, data dianalisis dengan cara analisis domain, taksonomi, komponensial, dan tema budaya. Hasil penelitian ini menunjukkan bahwa terjemahan dalam novel Insurgent mempunyai nilai keakuratan dan keberterimaan yang cukup tinggi. Berdasarkan penelitian ini, dapat disimpulkan bahwa tingkat keakuratan dan keberterimaan pada setiap jenis tindak tutur komisif memiliki dampak terhadap kualitas keseluruhan terjemahan kalimat yang mengandung tindak tutur komisif.Commissive speech act is one of the pragmatic aspects to regard by the translator in translating the text. It aims to produce a qualified translation in regarding accuracy and acceptability aspects. According to the aspects, this research aims to describe accuracy and acceptability of translation in sentences which accommodate commissive speech act using pragmatic approach. The data used is commissive speech and qualitative translation value result. The sources of the data are an Insurgent novel by Veronica Roth and informants. The data were collected through document analysis, questionnaire, and Focus Group Discussion then analyzed the domain, taxonomic, componential analysis, and cultural theme. The result shows that translation in the Insurgent novel has high accuracy and acceptability values. This research concludes that the accuracy and acceptability level in each commissive speech act has an impact on quality of whole translated sentences which contain commissive speech act.

The Impact of Competitive Quasi-Market on Service Delivery in Benue State University, Makurdi Nigeria

GIS Business ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. 85-98
Author(s):  
Idoko Peter
Keyword(s):  
Service Delivery ◽  
A Priori ◽  
Least Square ◽  
Secondary Source ◽  
State University ◽  
Ordinary Least Square ◽  
Negative Effect ◽  
The Impact ◽  
The Relationship

This research the impact of competitive quasi market on service delivery in Benue State University, Makurdi Nigeria. Both primary and secondary source of data and information were used for the study and questionnaire was used to extract information from the purposively selected respondents. The population for this study is one hundred and seventy three (173) administrative staff of Benue State University selected at random. The statistical tools employed was the classical ordinary least square (OLS) and the probability value of the estimates was used to tests hypotheses of the study. The result of the study indicates that a positive relationship exist between Competitive quasi marketing in Benue State University, Makurdi Nigeria (CQM) and Transparency in the service delivery (TRSP) and the relationship is statistically significant (p<0.05). Competitive quasi marketing (CQM) has a negative effect on Observe Competence in Benue State University, Makurdi Nigeria (OBCP) and the relationship is not statistically significant (p>0.05). Competitive quasi marketing (CQM) has a positive effect on Innovation in Benue State University, Makurdi Nigeria (INVO) and the relationship is statistically significant (p<0.05) and in line with a priori expectation. This means that a unit increases in Competitive quasi marketing (CQM) will result to a corresponding increase in innovation in Benue State University, Makurdi Nigeria (INVO) by a margin of 22.5%. It was concluded that government monopoly in the provision of certain types of services has greatly affected the quality of service experience in the institution. It was recommended among others that the stakeholders in the market has to be transparent so that the system will be productive to serve the society effectively

Conceptual imposings of quality management of system of production of composite materials for it is rocket the space equipment

2017 ◽  
Vol 14 (4) ◽  
pp. 30-38
Author(s):  
V. G. Isaev ◽  
T. N. Antipova
Keyword(s):  
Composite Materials ◽  
Quality Management ◽  
Evaluation Criteria ◽  
Criteria And Indicators ◽  
Properties Of Materials ◽  
A Priority ◽  
Required Quality

Basic provisions of the concept and methodology of production of composite materials for the missile and space equipment are offered. The system of the purposes realizing the principle of a priority of the purposes of the customer is offered. The system of evaluation criteria and indicators of quality of composite materials the realizing interrelation of requirements of the customer to quality of material and dependence of ensuring the required quality on the used technologies is developed. It is shown that for ensuring quality of composite materials for units and the RKT systems first of all it is necessary development of mathematical dependences of properties of materials on parameters of the technological modes in the conditions of obligatory implementation of requirements of the customer.

Coordination of technology of railway operation of the Republic of Tajikistan and organization of railways in international traffic

2018 ◽  
Vol 77 (4) ◽  
pp. 211-217 ◽  
Author(s):  
P. N. Pulatov
Keyword(s):  
Rolling Stock ◽  
Railway Transport ◽  
Transport Services ◽  
Railway Infrastructure ◽  
External Conditions ◽  
The Republic ◽  
Railway Operation ◽  
Required Quality

Current geopolitical and economic conditions for the functioning of railway transport in most post-Soviet states are such that it is extremely difficult to provide required quality of transport services and break-even operations at high expenses for maintaining the railway infrastructure and rolling stock. Dynamics of transportation of the Tajik Railway (TSR) is shown, which displays that most of its sections are classified as low-intensity ones. The paper proposes methodical principles, setting and qualitative analysis of the task of rationalization of operational work and organization of car flows for international transportation, taking into account the specifics of the Tajik Railway. There is a problem of complex maintenance of the efficiency of operational work in modern conditions based on the synthesis of the tasks of self-management (rational internal operational technology of the Tajik Railway) and coordination tasks (technological interaction with railway administrations of other states). Author substantiated the necessity of solving this problem. Proposed classification of technological restrictions and controlled variables in the performance of transport takes into account methods for changing external conditions for the functioning of the railway landfill and methods for increasing internal efficiency of its operation. The search for the solution of the problem involves direct search of variants along its ordered set with clipping of groups of variants that do not correspond to constraints, with the subsequent finding of compromise control over a set of effective alternatives.

Updated leg ulcer pathway: improving healing times and reducing costs

2019 ◽  
Vol 28 (20) ◽  
pp. S21-S26
Author(s):  
Leanne Atkin ◽  
Alison Schofield ◽  
Anita Kilroy-Findley
Keyword(s):  
Quality Of Life ◽  
Leg Ulcer ◽  
Leg Ulcers ◽  
Nursing Time ◽  
Venous Leg Ulcers ◽  
Reduced Costs ◽  
Reducing Costs

Regardless of the amount of literature and evidence on leg ulcer management, there are still significant variations in treatment. Implementing a standardised leg ulcer pathway to ensure patients are appropriately and timely assessed could help reduce nursing time and overall costs, while improving healing outcomes and patients' quality of life. Such a pathway was introduced in Lincolnshire and Leicestershire, UK, to treat venous leg ulcers (VLUs). The results showed improved healing times, reduced costs and fewer nurse visits, among other findings.

scholarly journals Physiological parameters of mental health predict the emergence of post-traumatic stress symptoms in physicians treating COVID-19 patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Dolev ◽  
S. Zubedat ◽  
Z. Brand ◽  
B. Bloch ◽  
E. Mader ◽  
...  
Keyword(s):  
Mental Health ◽  
Sleep Quality ◽  
Traumatic Stress ◽  
A Priori ◽  
Treatment Strategies ◽  
Physiological Measures ◽  
Post Traumatic Stress ◽  
Stress Symptoms ◽  
Post Traumatic

AbstractLack of established knowledge and treatment strategies, and change in work environment, may altogether critically affect the mental health and functioning of physicians treating COVID-19 patients. Thus, we examined whether treating COVID-19 patients affect the physicians’ mental health differently compared with physicians treating non-COVID-19 patients. In this cohort study, an association was blindly computed between physiologically measured anxiety and attention vigilance (collected from 1 May 2014 to 31 May 31 2016) and self-reports of anxiety, mental health aspects, and sleep quality (collected from 20 April to 30 June 2020, and analyzed from 1 July to 1 September 2020), of 91 physicians treating COVID-19 or non-COVID-19 patients. As a priori hypothesized, physicians treating COVID-19 patients showed a relative elevation in both physiological measures of anxiety (95% CI: 2317.69–2453.44 versus 1982.32–2068.46; P < 0.001) and attention vigilance (95% CI: 29.85–34.97 versus 22.84–26.61; P < 0.001), compared with their colleagues treating non-COVID-19 patients. At least 3 months into the pandemic, physicians treating COVID-19 patients reported high anxiety and low quality of sleep. Machine learning showed clustering to the COVID-19 and non-COVID-19 subgroups with a high correlation mainly between physiological and self-reported anxiety, and between physiologically measured anxiety and sleep duration. To conclude, the pattern of attention vigilance, heightened anxiety, and reduced sleep quality findings point the need for mental intervention aimed at those physicians susceptible to develop post-traumatic stress symptoms, owing to the consequences of fighting at the forefront of the COVID-19 pandemic.

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