Search results for: automotive lighting functions

Authors: Lee Kok Yueh, Fatin Hamadah Rahman, David Hassell, Au Thien Wan

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This work reports on a genre based study of lectures at a University in Brunei, Universiti Teknologi Brunei to explore the communicative functions and to gain insight into the discourse. It explores these in three different domains; Social Science, Engineering and Computing. Audio recordings from four lecturers comprising 20 lectures were transcribed and analysed, with the duration of each lecture varying between 20 to 90 minutes. This qualitative study found similar patterns and functions of lectures as those found in existing research amongst which include greetings, housekeeping, or recapping of previous lectures in the lecture introductions. In the lecture content, comprehension check and use of examples or analogies are very prevalent. However, the use of examples largely depend on the lecture content; and the more technical the content, the harder it was for lecturers to provide examples or analogies. Three functional moves are identified in the lecture conclusions; announcement, summary and future plan, all of which are optional. Despite the relatively small sample size, the present study shows that lectures are interactive and there are some consistencies with the delivery of lecture in relation to the communicative functions and genre of lecture.

Keywords: communicative functions, genre analysis, higher education, lectures

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Authors: Justyna Rybicka, Ashutosh Tiwari, Shane Enticott

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In the age of automation and computation aiding manufacturing, it is clear that manufacturing systems have become more complex than ever before. Although technological advances provide the capability to gain more value with fewer resources, sometimes utilisation of the manufacturing capabilities available to organisations is difficult to achieve. Flexible manufacturing systems (FMS) provide a unique capability to manufacturing organisations where there is a need for product range diversification by providing line efficiency through production flexibility. This is very valuable in trend driven production set-ups or niche volume production requirements. Although FMS provides flexible and efficient facilities, its optimal set-up is key in achieving production performance. As many variables are interlinked due to the flexibility provided by the FMS, analytical calculations are not always sufficient to predict the FMS’ performance. Simulation modelling is capable of capturing the complexity and constraints associated with FMS. This paper demonstrates how discrete event simulation (DES) can address complexity in an FMS to optimise the production line performance. A case study of an automotive FMS is presented. The DES model demonstrates different configuration options depending on prioritising objectives: utilisation and throughput. Additionally, this paper provides insight into understanding the impact of system set-up constraints on the FMS performance and demonstrates the exploration into the optimal production set-up.

Keywords: discrete event simulation, flexible manufacturing system, capacity performance, automotive

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Authors: G. Hemath Kumar, H. Mohit, K. Karthick

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One of the most important issues in the composite technology is the repairing of parts of aircraft structures which is manufactured from composite materials. In such applications and also for joining various composite parts together, they are fastened together either using adhesives or mechanical fasteners. The tensile strength of these joints was carried out using Universal Testing Machine (UTM). A parametric study was also conducted to compare the performance of the hybrid joint with varying adherent thickness, adhesive thickness and overlap length. The composition of the material is combination of epoxy resin and carbon fibre under the method of reinforcement. To utilize the full potential of composite materials as structural elements, the strength and stress distribution of these joints must be understood. The study of tensile strength in the members involved under various design conditions and various joints were took place.

Keywords: carbon fiber, FRP composite, MMC, automotive

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Authors: Un-Hwan Park, Jun-Hyeok Heo, In-Sung Lee, Tae-Hyeon Oh, Dae-Gyu Park

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Nonwoven fabric such as an automobile interior material becomes consists of several material layers required for the sound-absorbing function. Because several material layers, many experimental tuning is required to achieve the target of sound absorption. Therefore, a lot of time and money is spent in the development of the car interior materials. In this study, we present the method to predict the sound-absorbing performance of the various layers with physical properties of each material. and we will verify it with the measured value of a prototype. If the sound absorption can be estimated, it can be optimized without a number of tuning tests of the interiors. So, it can reduce the development cost and time during development

Keywords: automotive interior material, sound absorbing, optimization design, nonwoven fabric

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Authors: Nisreen Ardda

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Fenestrations are one of the main building envelope elements that play an important role in home social-ecological l factors. They play a vital role in providing natural lighting and ventilation, visual, thermal, and acoustical comfort, and also provide weather-tightness, privacy, a feeling of openness. In most home buildings, fenestrations are controlled manually by the occupants, which significantly impacts occupants' comfort and energy use. Culture plays a central role in the Palestinians window operation behavior. Improved windows design that provides the desired privacy while maintaining the appropriate function of fenestration (natural lighting, thermal comfort, and visual openness) is becoming a necessity. Therefore, this paper proposes a window typology to achieve the social and environmental factors in residential buildings in the West Bank. The window typology and reference building were designed in Rivet 2021, and natural ventilation was carried out in Design Builder 4.3.0.039. The results showed that the proposed typology provides the desired privacy and the feeling of openness without compromising natural ventilation as the existing window did.

Keywords: window design, passive design, sustainable built environment, building material

Procedia PDF Downloads 158

Authors: Dorottya Horváth, Tímea Harmath-Tánczos

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Attention deficit hyperactivity disorder (ADHD) and learning disabilities are common neurocognitive disorders that can have a significant impact on a child's academic performance. ADHD is characterized by inattention, hyperactivity, and impulsivity, while learning disabilities are characterized by difficulty with specific academic skills, such as reading, writing, or math. The aim of this study was to investigate the working memory, executive, and attention functions of neurotypical children and children with ADHD and learning disabilities in order to fill the gaps in the Hungarian mean test scores of these cognitive functions in children with neurocognitive disorders. Another aim was to specify the neuropsychological differential diagnostic toolkit in terms of the relationships and peculiarities between these cognitive functions. The research question addressed in this study was: How do the working memory, executive, and attention functions of neurotypical children compare to those of children with ADHD and learning disabilities? A self-administered test battery was used as a research tool. Working memory was measured with the Non-Word Repetition Test, the Listening Span Test, the Digit Span Test, and the Reverse Digit Span Test; executive function with the Letter Fluency, Semantic Fluency, and Verb Fluency Tests; and attentional concentration with the d2-R Test. The data for this study was collected from 115 children aged 9-14 years. The children were divided into three groups: neurotypical children (n = 44), children with ADHD without learning disabilities (n = 23), and children with ADHD with learning disabilities (n = 48). The data was analyzed using a variety of statistical methods, including t-tests, ANOVAs, and correlational analyses. The results showed that the performance of children with neurocognitive involvement in working memory, executive functions, and attention was significantly lower than the performance of neurotypical children. However, the results of children with ADHD and ADHD with learning disabilities did not show a significant difference. The findings of this study are important because they provide new insights into the cognitive profiles of children with ADHD and learning disabilities and suggest that working memory, executive functions, and attention are all impaired in children with neurocognitive involvement, regardless of whether they have ADHD or learning disabilities. This information can be used to develop more effective diagnostic and treatment strategies for these disorders.

Keywords: ADHD, attention functions, executive functions, learning disabilities, working memory

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Authors: Maryamosadat Ghasemi, Reza Amrollahi

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Plasma equilibrium geometry has a great influence on the confinement and magnetohydrodynamic stability in tokamaks. The poloidal field (PF) system of a tokamak should be able to support this plasma equilibrium geometry. In this work the prepared numerical code based on radial basis functions are presented and used to solve the Grad–Shafranov (GS) equation for the axisymmetric equilibrium of tokamak plasma. The radial basis functions (RBFs) which is a kind of numerical meshfree method (MFM) for solving partial differential equations (PDEs) has appeared in the last decade and is developing significantly in the last few years. This technique is applied in this study to obtain the equilibrium configuration for Alborz Tokamak. The behavior of numerical solution convergences show the validation of this calculations.

Keywords: equilibrium, grad–shafranov, radial basis functions, Alborz Tokamak

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Authors: Zulfiye Ahan, Mustafa Dogu, Elcin Yilmaz

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The use of nonwoven textile materials in many application areas is rapidly increasing thanks to their versatile performance properties. The automotive industry is one of the largest sectors in the world with a potential market of more than 2 billion euros for nonwoven textile materials applications. Lightweight materials having higher mechanical performance, better sound and heat insulation properties are of interest in many applications. Since the usage of nonwoven surfaces provides many of these advantages, the demand for this kind of materials is gradually growing especially in the automotive industry. Nonwoven materials used in lightweight vehicles can contain economical and high strength thermoplastics as well as durable components such as glass fiber. By bringing these composite materials into foam structure containing micro or nanopores, products with high absorption ability, light and mechanically stronger can be fabricated. In this respect, our goal is to produce thermoplastic composite nonwoven by using nonwoven glass fiber fabric reinforced polypropylene (PP). Azodicarbonamide (ADC) was selected as a foaming agent and a thermal process was applied to obtain porous structure. Various foaming temperature ranges and residence times were studied to examine the foaming behaviour of the thermoplastic composite nonwoven. Physicochemical and mechanical tests were applied in order to analyze the characteristics of composite foams.

Keywords: composite nonwoven, thermoplastic foams, foaming agent, foaming behavior

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Authors: O. Poleshchuk, E. Komarov

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This paper presents a regression model for interval type-2 fuzzy sets based on the least squares estimation technique. Unknown coefficients are assumed to be triangular fuzzy numbers. The basic idea is to determine aggregation intervals for type-1 fuzzy sets, membership functions of whose are low membership function and upper membership function of interval type-2 fuzzy set. These aggregation intervals were called weighted intervals. Low and upper membership functions of input and output interval type-2 fuzzy sets for developed regression models are considered as piecewise linear functions.

Keywords: interval type-2 fuzzy sets, fuzzy regression, weighted interval

Procedia PDF Downloads 334

Authors: Zulfiye Ahan, Mustafa Dogu, Elcin Yilmaz

Abstract:

The use of nonwoven textile materials in many application areas is rapidly increasing thanks to their versatile performance properties. The automotive industry is one of the largest sectors in the world, with a potential market of more than 2 billion euros for nonwoven textile materials applications. Lightweight materials having higher mechanical performance, better sound and heat insulation properties are of interest in many applications. Since the usage of nonwoven surfaces provides many of these advantages, the demand for this kind of material is gradually growing, especially in the automotive industry. Nonwoven materials used in lightweight vehicles can contain economical and high strength thermoplastics as well as durable components such as glass fiber. By bringing these composite materials into foam structure containing micro or nanopores, products with high absorption ability, light and mechanically stronger can be fabricated. In this respect, our goal is to produce thermoplastic composite nonwoven by using nonwoven glass fiber fabric reinforced polypropylene (PP). Azodicarbonamide (ADC) was selected as a foaming agent, and a thermal process was applied to obtain a porous structure. Various foaming temperature ranges and residence times were studied to examine the foaming behaviour of the thermoplastic composite nonwoven. Physicochemical and mechanical tests were applied in order to analyze the characteristics of composite foams.

Keywords: composite nonwoven, thermoplastic foams, foaming agent, foaming behavior

Procedia PDF Downloads 188

Authors: Hasan Muslemani, Jeffrey Wilson, Xi Liang, Francisco Ascui, Katharina Kaesehage

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This paper aims to examine consumer behaviour towards, and the willingness to adopt, green steel use in the automotive sector, in order to identify potential barriers and opportunities for its widespread adoption. Semi-structured interviews were held with experts from global, regional and country-specific industry associations and automakers. The analysis shows there is a new shift towards lifecycle thinking in the sector, although these efforts have been voluntary and driven by customer and employee pressures rather than regulation. The paper further appraises possible demand for green steel within different vehicle types (based on size and powertrain), and shows that manufacturers of electric heavy-duty vehicles are most likely to adopt green steel in the first instance, given the amount of incorporated steel in the vehicles and the fact that lifecycle emissions lie predominantly in their manufacturing phase. A case for green advanced higher-strength steels (AHSS) can also be made in light-duty passenger vehicles, which may mitigate competition from light-weight alternative materials in terms of cost and greenness (depending on source and utilisation zones). This work builds on a wide sustainability-related literature in the automotive sector and highlights areas in need of urgent action if the sector as a whole were to meet its Paris Agreement climate targets, in particular a need to revisit current CO2 performance regulations to include Scope 1 and Scope 2 emissions, engage in educational green marketing campaigns, and explore innovative market-based mechanisms to bridge the gap between relatively-low carbon abatement costs of steelmaking and high abatement costs of vehicle manufacturing.

Keywords: Green steel, Consumer behaviour, Automotive industry, Environmental sustainability

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Authors: Alexander Kospach, Fabian Benezeder, Jürgen Abraham

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E-mobility poses new challenges for inverters (e.g., higher switching frequencies) in terms of thermal behavior and thermal management. Due to even higher switching frequencies, thermal losses become greater, and the cooling of critical components (like insulated gate bipolar transistor and diodes) comes into focus. New manufacturing methods, such as 3D printing, enable completely new pin-fin structures that can handle higher waste heat to meet the new thermal requirements. Based on the geometrical specifications of the industrial partner regarding the manufacturing possibilities for 3D printing, different and completely new pin-fin structures were numerically investigated for their hydraulic and thermal behavior in fundamental studies assuming an indirect liquid cooling. For the 3D computational fluid dynamics (CFD) thermal simulations OpenFOAM was used, which has as numerical method the finite volume method for solving the conjugate heat transfer problem. A steady-state solver for turbulent fluid flow and solid heat conduction with conjugate heat transfer between solid and fluid regions was used for the simulations. In total, up to fifty pinfin structures and arrangements, some of them completely new, were numerically investigated. On the basis of the results of the principal investigations, the best two pin-fin structures and arrangements for the complete module cooling of an automotive inverter were numerically investigated and compared. There are clear differences in the maximum temperatures for the critical components, such as IGTBs and diodes. In summary, it was shown that 3D pin fin structures can significantly contribute to the improvement of heat transfer and cooling of an automotive inverter. This enables in the future smaller cooling designs and a better lifetime of automotive inverter modules. The new pin fin structures and arrangements can also be applied to other cooling applications where 3D printing can be used.

Keywords: pin fin heat sink optimization, 3D printed pin fins, CFD simulation, power electronic cooling, thermal management

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Authors: Ali E. Abbas

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Industrial Engineering is a broad multidisciplinary field with intersections and applications in numerous areas. When designing a product, it is important to determine the appropriate attributes of value and the preference function for which the product is optimized. This paper provides some guidelines on appropriate selection of attributes for preference and value functions for engineering design.

Keywords: decision analysis, industrial engineering, direct vs. indirect values, engineering management

Procedia PDF Downloads 276

Authors: Ching-Yuan Huang, Rhay-Hung Weng, Yi-Ting Chen

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Mentoring functions will improve new nurses' job performance, provide support with new nurses, and then reduce the turnover rate of them. This study explored the impact of transformational leadership and interpersonal interaction on mentoring functions. We employed a questionnaire survey to collect data and selected a sample of new nurses from three hospitals in Taiwan. A total of 306 valid surveys were obtained. Multiple regression model analysis was conducted to test the study hypothesis. Inspirational motivation, idealized influence, and individualized consideration had a positive influence on overall mentoring function, but intellectual stimulation had a positive influence on career development function only. Perceived similarity and interaction frequency also had positive influences on mentoring functions. When the shift overlap rate exceeded 80%, mentoring function experienced a negative result. The transformational leadership of mentors actually would improve the mentoring functions among new staff nurses. Perceived similarity and interaction frequency between mentees and mentors also had a positive influence on mentoring functions. Managers should enhance the transformational leadership of mentors by designing leadership training and motivation programs. Furthermore, nursing managers should promote the interaction between new staff nurses and their mentors, but the shift overlap rate should not exceed 80%.

Keywords: interpersonal interaction, mentoring function, mentor, new nurse, transformational leadership

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Authors: Achim Kampker, Heiner Hans Heimes, Mathias Ordung, Jan-Philip Ganser

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In the past years, the automotive industry has changed significantly. Innovative mobility concepts have become more important, and electric vehicles see a chance of replacing vehicles with combustion engines in the long term. However, the coming years will be characterized by coexistence. In this context, there are two possible production scenarios: One the one hand, electric vehicles could be manufactured in bespoke assembly lines. Concerning the uncertainty regarding sales figures development, this alternative boasts a high investment risk. Therefore, an integrated assembly building upon existing structures also seems a feasible solution. This empirical study aims at validating hypotheses concerning theoretical and practical challenges of the integrated production in the final assembly. In order to take a test of approaches of the research by analyzing censored feedback of professionals, these hypotheses are validated in the framework of an expert study. For this purpose, hypotheses have been generated on the basis of a requirements analysis and a concept specification. Thereupon, a list of question has been implemented and deduced from the hypotheses to execute an online- and written-survey and interviews with professionals. The interpretation and evaluation of the findings includes an inter-component comparison for the electric drivetrain. Furthermore, key drivers for a sufficient integrated product and process design are presented.

Keywords: automotive industry, final assembly, integrated manufacturing, product and process development

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Authors: Halil Ibrahim Demir, Caner Erden, Mumtaz Ipek, Ozer Uygun

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Traditionally, the three important manufacturing functions, which are process planning, scheduling and due-date assignment, are performed separately and sequentially. For couple of decades, hundreds of studies are done on integrated process planning and scheduling problems and numerous researches are performed on scheduling with due date assignment problem, but unfortunately the integration of these three important functions are not adequately addressed. Here, the integration of these three important functions is studied by using genetic, random-genetic hybrid, simulated annealing, random-simulated annealing hybrid and random search techniques. As well, the importance of the integration of these three functions and the power of meta-heuristics and of hybrid heuristics are studied.

Keywords: process planning, weighted scheduling, weighted due-date assignment, genetic search, simulated annealing, hybrid meta-heuristics

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Authors: M. Sazali Said, Rahim Jamian, Shahrizan Yusoff, Shahruzaman Sulaiman, Jum'Azulhisham Abdul Shukor

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This case study focuses on the role of Universiti Kuala Lumpur Malaysian Spanish Institute (UniKL MSI) to produce technologist in order to reduce the shortage of skilled workers especially in the automotive industry. The purpose of the study therefore seeks to examine the effectiveness of Technical Education and Vocational Training (TEVT) curriculum of UniKL MSI to produce graduates that could immediately be productively employed by the automotive industry. The approach used in this study is through performance evaluation of students attending the Industrial Training Attachment (INTRA). The sample of study comprises of 37 students, 16 university supervisors and 26 industrial supervisors. The research methodology involves the use of quantitative and qualitative methods of data collections through the triangulation approach. The quantitative data was gathered from the students, university supervisors and industrial supervisors through the use of questionnaire. Meanwhile, the qualitative data was obtained from the students and university supervisors through the use of interview and observation. Both types of data have been processed and analyzed in order to summarize the results in terms of frequency and percentage by using a computerized spread sheet. The result shows that industrial supervisors were satisfied with the students’ performance. Meanwhile, university supervisors rated moderate effectiveness of the UniKL MSI curriculum in producing graduates with appropriate skills and in meeting the industrial needs. During the period of study, several weaknesses in the curriculum have been identified for further continuous improvements. Recommendations and suggestions for curriculum improvement also include the enhancement of technical skills and competences of students towards fulfilling the needs and demand of the automotive industries.

Keywords: technical education and vocational training (TEVT), industrial training attachment (INTRA), curriculum improvement, automotive industry

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Authors: Jose Ruiz, Jose Velasquez, Holger Lovon

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Peruvian university buildings are critical structures for which very little research about its seismic vulnerability is available. This paper develops a probabilistic methodology that predicts seismic loss for university buildings with simulated fragility functions. Two university buildings located in the city of Cusco were analyzed. Fragility functions were developed considering seismic and structural parameters uncertainty. The fragility functions were generated with the Latin Hypercube technique, an improved Montecarlo-based method, which optimizes the sampling of structural parameters and provides at least 100 reliable samples for every level of seismic demand. Concrete compressive strength, maximum concrete strain and yield stress of the reinforcing steel were considered as the key structural parameters. The seismic demand is defined by synthetic records which are compatible with the elastic Peruvian design spectrum. Acceleration records are scaled based on the peak ground acceleration on rigid soil (PGA) which goes from 0.05g to 1.00g. A total of 2000 structural models were considered to account for both structural and seismic variability. These functions represent the overall building behavior because they give rational information regarding damage ratios for defined levels of seismic demand. The university buildings show an expected Mean Damage Factor of 8.80% and 19.05%, respectively, for the 0.22g-PGA scenario, which was amplified by the soil type coefficient and resulted in 0.26g-PGA. These ratios were computed considering a seismic demand related to 10% of probability of exceedance in 50 years which is a requirement in the Peruvian seismic code. These results show an acceptable seismic performance for both buildings.

Keywords: fragility functions, university buildings, loss assessment, Montecarlo simulation, latin hypercube

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Authors: Eniko Nagy, Csaba Csiszar

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Satisfaction of air transportation passengers is significantly affected by the perceived quality of airport information services. The development potential of ICT is considerable. The traditional and new functions of ‘smart’ airports are realized by complex services aiding seamless, comfortable and less time-consuming travel. Based on the elements of the transportation chain the information management functions, their relationships and the technical solutions have been identified. The functions have been categorized by their development level and evaluation scores have been assigned to each category. Correction factors influencing the usefulness of the technology or the service have been introduced. A method for the calculation of ‘smart’ index in order to compare the airports in objective way has been developed; thus facilitating further developments. The method has been applied for the case study of Budapest.

Keywords: air transportation informatics, evaluation, information service, smart airport

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Authors: C. A. Barros, Ana P. Barroso

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Any industrial company needs to determine the amount of variation that exists within its measurement process and guarantee the reliability of their data, studying the performance of their measurement system, in terms of linearity, bias, repeatability and reproducibility and stability. This issue is critical for automotive industry suppliers, who are required to be certified by the 16949:2016 standard (replaces the ISO/TS 16949) of International Automotive Task Force, defining the requirements of a quality management system for companies in the automotive industry. Measurement System Analysis (MSA) is one of the mandatory tools. Frequently, the measurement system in companies is not connected to the equipment and do not incorporate the methods proposed by the Automotive Industry Action Group (AIAG). To address these constraints, an R&D project is in progress, whose objective is to develop a web and cloud-based MSA tool. This MSA tool incorporates Industry 4.0 concepts, such as, Internet of Things (IoT) protocols to assure the connection with the measuring equipment, cloud computing, artificial intelligence, statistical tools, and advanced mathematical algorithms. This paper presents the preliminary findings of the project. The web and cloud-based MSA tool is innovative because it implements all statistical tests proposed in the MSA-4 reference manual from AIAG as well as other emerging methods and techniques. As it is integrated with the measuring devices, it reduces the manual input of data and therefore the errors. The tool ensures traceability of all performed tests and can be used in quality laboratories and in the production lines. Besides, it monitors MSAs over time, allowing both the analysis of deviations from the variation of the measurements performed and the management of measurement equipment and calibrations. To develop the MSA tool a ten-step approach was implemented. Firstly, it was performed a benchmarking analysis of the current competitors and commercial solutions linked to MSA, concerning Industry 4.0 paradigm. Next, an analysis of the size of the target market for the MSA tool was done. Afterwards, data flow and traceability requirements were analysed in order to implement an IoT data network that interconnects with the equipment, preferably via wireless. The MSA web solution was designed under UI/UX principles and an API in python language was developed to perform the algorithms and the statistical analysis. Continuous validation of the tool by companies is being performed to assure real time management of the ‘big data’. The main results of this R&D project are: MSA Tool, web and cloud-based; Python API; New Algorithms to the market; and Style Guide of UI/UX of the tool. The MSA tool proposed adds value to the state of the art as it ensures an effective response to the new challenges of measurement systems, which are increasingly critical in production processes. Although the automotive industry has triggered the development of this innovative MSA tool, other industries would also benefit from it. Currently, companies from molds and plastics, chemical and food industry are already validating it.

Keywords: automotive Industry, industry 4.0, Internet of Things, IATF 16949:2016, measurement system analysis

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Authors: Jung-Ho Moon, Tae Kwon Ha

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Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require systematic investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 300 series austenitic stainless steels have been evaluated in the temperature ranges of 200-800°C and 200-900°C. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property.

Keywords: austenitic stainless steel, automotive exhaust, thermal fatigue, microstructure, load relaxation

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Authors: Achim Kampker, Kai Kreiskoether, Johannes Wagner, Sarah Fluchs

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The growing speed of innovation in related industries requires the automotive industry to adapt and increase release frequencies of new vehicle derivatives which implies a significant reduction of investments per vehicle and ramp-up times. Emerging markets in various parts of the world augment the currently dominating established main automotive markets. Local content requirements such as import tariffs on final products impede the accessibility of these micro markets, which is why in the future market exploitation will not be driven by pure sales activities anymore but rather by setting up local assembly units. The aim of this paper is to provide an overview of the concept of decentralized assembly and to discuss and critically assess some currently researched and crucial approaches in production technology. In order to determine the scope in which complementary mobile assembly can be profitable for manufacturers, a general cost model is set up and each cost driver is assessed with respect to varying levels of decentralization. One main result of the paper is that the presented approaches offer huge cost-saving potentials and are thus critical for future production strategies. Nevertheless, they still need to be further exploited in order for decentralized assembly to be profitable for companies. The optimal level of decentralization must, however, be specifically determined in each case and cannot be defined in general.

Keywords: automotive assembly, e-mobility, production technology, release capability, small series assembly

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Authors: Yi-Fei Yang, Nai-Bao He, Shao-Bang Xing

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This study investigates the permanent magnet synchronous linear motor (PMSLM) chaotic motion under the specific physical parameters, the stability and the security of motor-driven system will be unavoidably influenced. Therefore, it is really necessary to investigate the methods of controlling or suppressing chaos in PMSLM. Firstly, we derive a chaotic model of PMSLM in the closed-loop system. Secondly, in order to realize the local asymptotic stabilization of the mechanical subsystem and the global stabilization of the motor-driven system including electrical subsystem, we propose an improved uniting control lyapunov functions by introducing backstepping approach. Finally, an illustrated example is also given to show the electiveness of the obtained results.

Keywords: linear motor, lyapunov functions, chao control, hybrid controller

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Authors: Joe Kallas

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It is now widely accepted that the preservation of cultural heritage must go beyond simple restoration and renovation actions. While some historic monuments have been preserved for millennia, many of them, less important or simply neglected because of lack of money, have disappeared. As a result, the adaptation of monuments and archaeological sites to new functions allow them to 'survive'. Temporary activities or 'ephemeral' re-use, are increasingly recognized as a means of vitalization of deprived areas and enhancement of historic sites that became obsolete. They have the potential to increase economic and cultural value while making the best use of existing resources. However, there are often conservation and preservation issues related to the implementation of this type of re-use, which can also threaten the integrity and authenticity of archaeological sites and monuments if they have not been properly managed. This paper aims to get a better knowledge of the ephemeral re-use of heritage, and more specifically the subject of the incorporation of the festival phenomenon within the monuments and archaeological sites in Lebanon, a topic that is not yet studied enough. This paper tried to determine the elements that compose it, in order to analyze this phenomenon and to trace its good practices, by comparing international study cases to important national cases: the International Festival of Baalbek, the International Festival of Byblos and the International Festival of Beiteddine. Various factors have been studied and analyzed in order to best respond to the main problematic of this paper: 'How can we preserve the integrity of sites and monuments after the integration of an ephemeral function? And what are the preventive conservation measures to be taken when holding festivals in archaeological sites with fragile structures?' The impacts of the technical problems were first analyzed using various data and more particularly the effects of mass tourism, the integration of temporary installations, sound vibrations, the effects of unstudied lighting, until the mystification of heritage. Unfortunately, the DGA (General Direction of Antiquities in Lebanon) does not specify any frequency limit for the sound vibrations emitted by the speakers during musical festivals. In addition, there is no requirement from its part regarding the installations of the lighting systems in the historic monuments and no monitoring is done in situ, due to the lack of awareness of the impact that could be generated by such interventions, and due to the lack of materials and tools needed for the monitoring process. The study and analysis of the various data mentioned above led us to the elaboration of the main objective of this paper, which is the establishment of a list of recommendations. This list enables to define various preventive conservation measures to be taken during the holding of the festivals within the cultural heritage sites in Lebanon. We strongly hope that this paper will be an awareness document to start taking into consideration several factors previously neglected, in order to improve the conservation practices in the archaeological sites and monuments during the incorporation of the festival phenomenon.

Keywords: archaeology, authenticity, conservation, cultural heritage, festival, historic sites, integrity, monuments, tourism

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Authors: Al Omari Moahmmed Ahmed

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These papers describe the Bayesian Estimator using Markov Chain Monte Carlo and Lindley’s approximation and the maximum likelihood estimation of the Weibull distribution with Type-I censored data. The maximum likelihood method can’t estimate the shape parameter in closed forms, although it can be solved by numerical methods. Moreover, the Bayesian estimates of the parameters, the survival and hazard functions cannot be solved analytically. Hence Markov Chain Monte Carlo method and Lindley’s approximation are used, where the full conditional distribution for the parameters of Weibull distribution are obtained via Gibbs sampling and Metropolis-Hastings algorithm (HM) followed by estimate the survival and hazard functions. The methods are compared to Maximum Likelihood counterparts and the comparisons are made with respect to the Mean Square Error (MSE) and absolute bias to determine the better method in scale and shape parameters, the survival and hazard functions.

Keywords: weibull distribution, bayesian method, markov chain mote carlo, survival and hazard functions

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Authors: M. Saifudin Ahmed Atique, Santosh Paudyal, Caixia Yang

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In an aircraft, a great portion of energy is wasted due to its inflight structural vibration. Structural components vibrate due to aeroelastic instabilities, gust perturbations and engine rotation at very high rpm. Energy losses due to mechanical vibration can be utilized by harvesting energy from aircraft structure as electrical energy. This harvested energy can be stored in battery panels built into aircraft fuselage and can be used to power inflight auxiliary accessories i.e., lighting and entertainment systems. Moreover, this power can be used for wireless Structural Health Monitoring System (SHM) for aircraft and as an excellent replacement of aircraft Ground Power Unit (GPU)/Auxiliary Power Unit (APU) during passenger onboard time to power aircraft cabin accessories to reduce aircraft ground operation cost significantly. In this paper, we propose the design of a noble aircraft wing in which Piezoelectric panels placed under the composite skin of aircraft wing will generate electrical charges from any inflight aerodynamics or mechanical vibration and store it into battery to power auxiliary inflight systems/accessories as per requirement. Experimental results show that a well-engineered piezoelectric energy harvester based aircraft wing can produce adequate energy to support in-flight lighting and auxiliary cabin accessories.

Keywords: vibration energy, aircraft wing, piezoelectric material, inflight accessories

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Authors: Halil Ibrahim Demir, Alper Goksu, Onur Canpolat, Caner Erden, Melek Nur

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Traditionally process planning, scheduling and due date assignment are performed sequentially and separately. High interrelation between these functions makes integration very useful. Although there are numerous works on integrated process planning and scheduling and many works on scheduling with due date assignment, there are only a few works on the integration of these three functions. Here we tested the different integration levels of these three functions and found a fully integrated version as the best. We applied genetic search and random search and genetic search was found better compared to the random search. We penalized all earliness, tardiness and due date related costs. Since all these three terms are all undesired, it is better to penalize all of them.

Keywords: process planning, scheduling, due-date assignment, genetic algorithm, random search

Procedia PDF Downloads 347

Authors: Amanpreet Kaur

Abstract:

Wavelet transform (WT) is a powerful statistical tool used in applied mathematics for signal and image processing. The different mother, wavelet basis function, has been compared to select the optimal wavelet function that represents the electromyogram signal characteristics of upper limb amputees. Four different EMG electrode has placed on different location of shoulder muscles. Twenty one wavelet functions from different wavelet families were investigated. These functions included Daubechies (db1-db10), Symlets (sym1-sym5), Coiflets (coif1-coif5) and Discrete Meyer. Using mean square error value, the significance of the mother wavelet functions has been determined for teres, pectorals, and infraspinatus around shoulder muscles. The results show that the best mother wavelet is the db3 from the Daubechies family for efficient classification of the signal.

Keywords: Daubechies, upper limb amputation, shoulder muscles, Symlets, Coiflets

Procedia PDF Downloads 213

Authors: Seyed Esmail Seyedi Bariran, Khairul Salleh Mohamed Sahari

Abstract:

In multi-echelon supply chain networks, optimal supplier selection significantly depends on the accuracy of suppliers’ performance prediction. Different methods of multi criteria decision making such as ANN, GA, Fuzzy, AHP, etc have been previously used to predict the supplier performance but the “black-box” characteristic of these methods is yet a major concern to be resolved. Therefore, the primary objective in this paper is to implement an artificial intelligence-based gene expression programming (GEP) model to compare the prediction accuracy with that of ANN. A full factorial design with %95 confidence interval is initially applied to determine the appropriate set of criteria for supplier performance evaluation. A test-train approach is then utilized for the ANN and GEP exclusively. The training results are used to find the optimal network architecture and the testing data will determine the prediction accuracy of each method based on measures of root mean square error (RMSE) and correlation coefficient (R2). The results of a case study conducted in Supplying Automotive Parts Co. (SAPCO) with more than 100 local and foreign supply chain members revealed that, in comparison with ANN, gene expression programming has a significant preference in predicting supplier performance by referring to the respective RMSE and R-squared values. Moreover, using GEP, a mathematical function was also derived to solve the issue of ANN black-box structure in modeling the performance prediction.

Keywords: Supplier Performance Prediction, ANN, GEP, Automotive, SAPCO

Procedia PDF Downloads 389

Authors: Dario Basile, Manuela De Maddis, Raffaella Sesana, Pasquale Russo Spena, Roberto Maiorano

Abstract:

Nowadays, the reduction of CO₂ emissions and the decrease in energy consumption are the main aims of several industries, especially in the automotive sector. To comply with the increasingly restrictive regulations, the automotive industry is constantly looking for innovative techniques to produce lighter, more efficient, and less polluting vehicles. One of the latest technologies, and still developing, is based on the fabrication of the body-in-white and car parts through the stamping of Aluminum Tailor Welded Blanks. Tailor Welded Blanks (TWBs) are generally the combination of two/three metal sheets with different thicknesses and/or mechanical strengths, which are commonly butt-welded together by laser sources. The use of aluminum TWBs has several advantages such as low density and corrosion resistance adequate. However, their use is still limited by the lower formability with respect to the parent materials and the more intrinsic difficulty of laser welding of aluminum sheets (i.e., internal porosity) that, although its use in automated industries is constantly growing, remains a process to be further developed and improved. This study has investigated the effect of the main laser welding process parameters (laser power, welding speed, and focal distance) on the mechanical properties of aluminum TWBs made of 6xxx series. The research results show that a narrow weldability window can be found to ensure welded joints with high strength and limited or no porosity.

Keywords: aluminum sheets, automotive industry, laser welding, mechanical properties, tailor welded blanks

Procedia PDF Downloads 80