An Investigation for the Potential of Improving the Performance of Pattern Making Process in Steel Foundries: Case Study

2014 ◽  
Vol 575 ◽  
pp. 900-904
Author(s):  
Mohammad Hayajneh ◽  
Mohammad D. AL-Tahat ◽  
Salman Alshobaki ◽  
Walid Khraisat
Keyword(s):  
Mathematical Model ◽  
Design And Technology ◽  
Flow Process ◽  
Pattern Design ◽  
Coding Scheme ◽  
Casting Quality ◽  
Design And Manufacturing ◽  
Complexity Classification ◽  
Casting Design

This paper aims to examine the opportunities for possible improvement of the systems of pattern design and manufacturing, as well as the processes of casting design and technology in steel foundries. Solving these problems will improve the casting quality, and it will also standardize the work in one of the major bottlenecks in the production of steel casting. One big Jordanian foundry is selected as a case study. The foundry is referred to as GAZAL throughout this paper. A detailed flow process chart for the pattern making process with standardized times is developed, then possible improvements to the process are proposed. Several important milestones were developed and documented, among that; the development of a complexity classification and coding scheme of 6 levels to classify the products that GAZAL produced based on several criteria’s; the development of a mathematical model that relate the production time of the pattern with the complexity level. Finally conclusions are presented at the end of the paper.

Perancangan dan Pembuatan Alat Bantu Meja Putar untuk Mesin Cnc 4 Axis

2016 ◽  
Vol 10 (2) ◽  
pp. 162-171
Author(s):  
Hafid Hafid ◽  
Tatang Sutisna
Keyword(s):  
Processing Time ◽  
Rotary Table ◽  
Engineering Process ◽  
Cnc Machine ◽  
Economical Analysis ◽  
Machining Center ◽  
Design And Manufacturing ◽  
The Cost ◽  
Productivity And Competitiveness

The design and manufacturing of the rotary table with the specification Ø 170 mm (6 inches) for CNC machine 4 axis has been done. The objective of manufacturing a rotary table is to increase the efficiency of CNC machine Hardford 4 axis to be above 80% in line machining center CV. IM’s workshop. The engineering methods was taken, consist of: working preparation, manufacturing of working drawing, engineering process, the manufacturing and testing. The prototype has been tested and operated, the resulting of increasing productivity of which were as follows: the process of assembling was increased to be 3 time ( before 1 time) and processing time for a specific case reduced from 5 hours to 3 hours, number of operators for the case of assembling the rotary reduced to 1 person (before 4 persons), safety and security become to be better. The results show increased efficiency of CNC machine Hardford, from under 50% to be above 80%. Based on the economical analysis obtained by the cost of good sold (C.G.S) of the rotary table is IDR 34.060.000. The results presented in this paper is expected to be case study for developing a business of the metal and engineering SMEs domestic to the effort of improving efficiency, quality, productivity and competitiveness in global market.ABSTRAKPerancangan dan pembuatan alat bantu meja putar (rotary table) dengan spesifikasi teknis Ø 170 mm (6 inci) untuk mesin CNC 4 axis telah dilakukan. Tujuan pembuatan rotary table adalah untuk meningkatkan efisiensi mesin CNC Hardford 4 axis di atas 80% pada line machining center Bengkel CV. IM. Metode rancang bangun yang dilakukan, meliputi: persiapan kerja, pembuatan gambar kerja, proses engineering, pembuatan dan uji coba. Prototip tersebut telah diuji coba dan dioperasikan dengan hasil peningkatan produktivitas sebagai berikut: proses pengerjaan bongkar pasang meningkat menjadi 3 kali (sebelumnya 1 kali) dan waktu pengerjaan untuk kasus tertentu berkurang dari 5 jam menjadi 3 jam, jumlah operator untuk kasus bongkar pasang rotary berkurang menjadi 1 orang (sebelumnya 4 orang), keselamatan kerja dan keamanan menjadi lebih baik. Hasil peningkatan berupa efisiensi mesin CNC Hardford 4 axis dari sebelumnya di bawah 50% menjadi di atas 80%. Berdasarkan hasil perhitungan analisis ekonomi diperoleh harga pokok produksi (HPP) alat bantu meja putar adalah sebesar Rp. 34.060.000. Bahasan ini diharapkan menjadi contoh kasus bagi pengembangan usaha IKM logam dan mesin dalam negeri untuk meningkatkan efisiensi, mutu, produktivitas dan keunggulan daya saing di pasar global.Kata kunci: alat bantu meja putar, mesin CNC, harga pokok produksi

Modelling and Simulation of NO2 Dispersion Phenomenon in Atmosphere by Analytical-Experimental Methods

2008 ◽  
Vol 59 (10) ◽  
Author(s):  
Delia Perju ◽  
Harieta Pirlea ◽  
Gabriela-Alina Brusturean ◽  
Dana Silaghi-Perju ◽  
Sorin Marinescu
Keyword(s):  
Mathematical Model ◽  
Nitrogen Dioxide ◽  
Modeling And Simulation ◽  
Human Health ◽  
Experimental Methods ◽  
Negative Effects ◽  
Real Situation ◽  
Experimental Values ◽  
The Mathematical Model

The European laws and recently the Romanian ones impose more and more strict norms to the large nitrogen dioxide polluters. They are obligated to continuously improve the installations and products so that they limit and reduce the nitrogen dioxide pollution, because it has negative effects on the human health and environment. In this paper are presented these researches made within a case study for the Timi�oara municipality, regarding the modeling and simulation of the nitrogen dioxide dispersion phenomenon coming from various sources in atmosphere with the help of analytical-experimental methods. The mathematical model resulting from these researches is accurately enough to describe the real situation. This was confirmed by comparing the results obtained based on the model with real experimental values.

Product Analysis and Variants Derivation Based on a Semantically Annotated Product Family Ontology

2009 ◽  
Author(s):  
Soon Chong Johnson Lim ◽  
Ying Liu ◽  
Wing Bun Lee
Keyword(s):  
Semantic Annotation ◽  
Product Family ◽  
Relevant Information ◽  
Product Analysis ◽  
Laptop Computer ◽  
Family Analysis ◽  
Design And Manufacturing ◽  
Commonality Analysis ◽  
Current Representation

In literature, there are a number of indexes suggested that serve as the indicator of commonality among product components, modules and variants. However, as these elements are increasingly interconnected with aspects other than the component view, the existing commonality metrics are unable to effectively model these aspects due to their limitation in capturing relevant information for analysis. Therefore, there exists a need to consider multiple design and manufacturing aspects in commonality metrics so that a comprehensive view of the commonality among product variants can be presented. In the current representation schemes proposed for product family modeling, ontology is one of the most promising ones to model the complex semantic relations among various elements in a product family. Nevertheless, the research and application of ontology in the analysis of a product family has so far received little attention. In this paper, we proposed a framework to generate a semantically annotated multi-facet product family ontology. Using a case study of a laptop computer family, we suggest and demonstrate a new commonality analysis approach based on the semantically annotated multi-facet laptop product family ontology. Together with a new method of deriving product variants based on the aforementioned ontology, our approach illustrates the merits of using semantic annotation in assisting ontology based product family analysis.

Study on the Calculation Method of Soil-Nailing for High Soil Slope Based on the Logarithmic Spiral Slippery Fracture

2011 ◽  
Vol 261-263 ◽  
pp. 1709-1713
Author(s):  
Meng Yang ◽  
Xiao Min Liu
Keyword(s):  
Mathematical Model ◽  
Stability Analysis ◽  
Engineering Design ◽  
Calculation Method ◽  
Logarithmic Spiral ◽  
Soil Nailing ◽  
Soil Slope ◽  
Mode Pattern ◽  
Shear Function

This paper introduces a new failure mode pattern of soil slope – the logarithmic spiral slippery fracture. A mathematical model for the logarithmic spiral slippery fracture is established, taking the anti-shear function of the soil-nailing into consideration. The shear of soil-nailing, axial force, and the safety coefficients based on the limiting equilibrium method are derived, leading to an accurate stability analysis of the strengthening of soil slope. A case study shows that the anti-shear function of the soil-nailing can be significant and should not be ignored in engineering design.

scholarly journals Improving the Downwind Sail Design Process by Means of a Novel FSI Approach

2021 ◽  
Vol 9 (6) ◽  
pp. 624
Author(s):  
Antonino Cirello ◽  
Tommaso Ingrassia ◽  
Antonio Mancuso ◽  
Vincenzo Nigrelli ◽  
Davide Tumino
Keyword(s):  
Numerical Methods ◽  
Low Cost ◽  
The Novel ◽  
The Real ◽  
Weakly Coupled ◽  
Design And Manufacturing ◽  
Sailing Yacht ◽  
Computational Resources ◽  
Effective Use

The process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in evaluating and optimizing downwind sail performance and manufacturing. A new weakly coupled fluid–structure interaction (FSI) procedure has been developed to study downwind sails. The proposed method is parametric and automated and allows for investigating multiple kinds of sails under different sailing conditions. The study of a gennaker of a small sailing yacht is presented as a case study. Based on the numerical results obtained, an analytical formulation for calculating the sail corner loads has been also proposed. The novel proposed methodology could represent a promising approach to allow for the widespread and effective use of numerical methods in the design and manufacturing of yacht sails.

scholarly journals A Control Based Mathematical Model for the Evaluation of Intervention Lines in COVID-19 Epidemic Spread: The Italian Case Study

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 890
Author(s):  
Paolo Di Giamberardino ◽  
Rita Caldarella ◽  
Daniela Iacoviello
Keyword(s):  
Mathematical Model ◽  
Equilibrium Points ◽  
Italian Case ◽  
Control Actions ◽  
Containment Measures ◽  
Asymptomatic Subjects ◽  
The Impact

This paper addresses the problem of describing the spread of COVID-19 by a mathematical model introducing all the possible control actions as prevention (informative campaign, use of masks, social distancing, vaccination) and medication. The model adopted is similar to SEIQR, with the infected patients split into groups of asymptomatic subjects and isolated ones. This distinction is particularly important in the current pandemic, due to the fundamental the role of asymptomatic subjects in the virus diffusion. The influence of the control actions is considered in analysing the model, from the calculus of the equilibrium points to the determination of the reproduction number. This choice is motivated by the fact that the available organised data have been collected since from the end of February 2020, and almost simultaneously containment measures, increasing in typology and effectiveness, have been applied. The characteristics of COVID-19, not fully understood yet, suggest an asymmetric diffusion among countries and among categories of subjects. Referring to the Italian situation, the containment measures, as applied by the population, have been identified, showing their relation with the government's decisions; this allows the study of possible scenarios, comparing the impact of different possible choices.

A bi-level mathematical model for logistic management considering the evolutionary game with environmental feedbacks

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peiman Ghasemi ◽  
Fariba Goodarzian ◽  
Angappa Gunasekaran ◽  
Ajith Abraham
Keyword(s):  
Mathematical Model ◽  
Lagrangian Relaxation ◽  
Evolutionary Games ◽  
Relaxation Method ◽  
Objective Functions ◽  
Content Type ◽  
Medical Centers ◽  
Location Routing ◽  
Proposed Model

PurposeThis paper proposed a bi-level mathematical model for location, routing and allocation of medical centers to distribution depots during the COVID-19 pandemic outbreak. The developed model has two players including interdictor (COVID-19) and fortifier (government). Accordingly, the aim of the first player (COVID-19) is to maximize system costs and causing further damage to the system. The goal of the second player (government) is to minimize the costs of location, routing and allocation due to budget limitations.Design/methodology/approachThe approach of evolutionary games with environmental feedbacks was used to develop the proposed model. Moreover, the game continues until the desired demand is satisfied. The Lagrangian relaxation method was applied to solve the proposed model.FindingsEmpirical results illustrate that with increasing demand, the values of the objective functions of the interdictor and fortifier models have increased. Also, with the raising fixed cost of the established depot, the values of the objective functions of the interdictor and fortifier models have raised. In this regard, the number of established depots in the second scenario (COVID-19 wave) is more than the first scenario (normal COVID-19 conditions).Research limitations/implicationsThe results of the current research can be useful for hospitals, governments, Disaster Relief Organization, Red Crescent, the Ministry of Health, etc. One of the limitations of the research is the lack of access to accurate information about transportation costs. Moreover, in this study, only the information of drivers and experts about transportation costs has been considered. In order to implement the presented solution approach for the real case study, high RAM and CPU hardware facilities and software facilities are required, which are the limitations of the proposed paper.Originality/valueThe main contributions of the current research are considering evolutionary games with environmental feedbacks during the COVID-19 pandemic outbreak and location, routing and allocation of the medical centers to the distribution depots during the COVID-19 outbreak. A real case study is illustrated, where the Lagrangian relaxation method is employed to solve the problem.

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