Improving correlation accuracy of crashworthiness applications by combining the CORA and MADM methods

With the increasing use of Computer Aided Engineering, it has become vital to be able to evaluate the accuracy of numerical models. This research poses the problem of selection of the most accurate and relevant correlation solution to a set of corridor variations. Specific methods such as CORA, widely accepted in industry, are developed to objectively evaluate the correlation between monotonic functions, while the Minimum Area Discrepancy Method, or MADM, is the only method to address the correlation of non-injective mathematical variations, usually related to force/acceleration versus displacement problems. Often, it is not possible to differentiate objectively various solutions proposed by CORA, which this paper proposes to answer. This research is original, as it proposes a new innovative correlation optimisation framework, which can select the best CORA solution by including MADM as a subsequent process. The paper and the methods are rigorous, having used an industry standard driver airbag computer model, built virtual test corridors and compared the relationship between different CORA and MADM ratings from 100 Latin Hypercube samples. For the same CORA value of ‘1’ (perfect correlation), MADM was capable to objectively differentiate between 13 of them and provide the best correlation possible. The paper has recommended the MADM settings n = 1; m = 2 or n = 3; m = 2 for a congruent relationship with CORA. As MADM is performed subsequently, this new framework can be implemented in already existing industrial processes and provide automotive manufacturers and Original Equipment Manufacturers (OEM) with a new tool to generate more accurate computer models.

Security and privacy enhancing mechanisms for the android operating system

Η πλατφόρμα Android αποτελεί το κυρίαρχο λειτουργικό σύστημα για κινητές και IoT συσκευές. Η ευρεία διάδοση του οφείλεται στην ελευθερία χρήσης που δίνετε στους κατασκευαστές κινητών συσκευών (Original Equipment Manufacturers - OEMs) να το χρησιμοποιούν ως το κύριο λειτουργικό σύστημα για τις συσκευές τους. Αφενός μεν, το μοντέλο ασφαλείας του Android προστατεύει τους χρήστες από τις απειλές των συμβατικών λειτουργικών συστημάτων όπως macOS, Windows, Linux, κλπ. Αφετέρου δε, στο Android εμφανίζονται αδυναμίες εξαιτίας των ιδιαιτεροτήτων της αρχιτεκτονικής του. Η παρούσα διδακτορική διατριβή επικεντρώνεται στο λειτουργικό σύστημα Android, τους μηχανισμούς ασφάλειας του, τις απειλές του, τα τρωτά σημεία του, και την αποτροπή σειράς επιθέσεων σε αυτό. Αρχικά διερευνάται το μοντέλο ελέγχου αδειών (permission model) του λειτουργικού συστήματος για τον περιορισμό της πρόσβασης σε ευαίσθητους πόρους από εφαρμογές και τη "σχέση" του με τις μεθόδους API (Application Programming Interface) του Android framework για την κατασκευή των συσχετίσεων αδειών (permissions) και των μεθόδων του framework. Η συσχέτιση μεταξύ μιας μεθόδου API του Android framework και ενός permission μπορεί να βρεθεί μέσω του documentation των μεθόδων του συστήματος Android. Ωστόσο, όχι μόνο το documentation μπορεί τυχαία να στερείται πληροφοριών αλλά και το Android διαθέτει undocumented και private μεθόδους API. Το αποτέλεσμα της ανάλυσης ήταν το Dypermin, ένα εργαλείο ικανό να συσχετίσει μεθόδους API και permissions χωρίς να απαιτείται τροποποίηση του υποκείμενου λειτουργικού συστήματος. Για να επιτευχθεί αυτό, το Dypermin αξιοποιεί τις εξαιρέσεις ασφαλείας (runtime Java security exceprtions) κατά τη διάρκεια εκτέλεσης μεθόδων του Android Framework και τη τεχνική reflection της γλώσσας προγραμματισμού Java για την προσπέλαση οποιασδήποτε προστατευμένης (private) μεθόδου API του Android Framework. Επιπλέον, το Dypermin, σε αντίθεση με άλλες σχετικές μεθόδους, βασίζεται σε πληροφορίες κατά τους χρόνους εκτέλεσης των μεθόδων API του Android framework, πράγμα που σημαίνει ότι δεν δημιουργεί ψευδώς θετικές (false positives) συσχετίσεις. Το Dypermin αξιολογήθηκε σε διαφορετικές εκδόσεις Android και τα αποτελέσματα του συγκρίθηκαν με αντίστοιχα αποτελέσματα άλλων προτεινόμενων μεθόδων για την ανάδειξη της αποτελεσματικότητα του για οποιαδήποτε έκδοση του συστήματος. Παράλληλα εξετάζονται οι επιθέσεις activity, και task hijacking στο λειτουργικό σύστημα Android που μπορούν να έχουν μεγάλο αντίκτυπο για τους χρήστες, καθώς κακόβουλες εφαρμογές που εκμεταλλεύονται τέτοιες αδυναμίες μπορούν να τους εξαπατήσουν και να αποκτήσουν πρόσβαση σε ευαίσθητα δεδομένα τους και λογαριασμούς τους. Αναμφίβολα, αυτές οι απειλές έχουν μεγάλη σημασία και για τη διεξοδική μελέτη τους, δημιουργήθηκε το εργαλείο Anactijax, ικανό να εντοπίσει συγκεκριμένες διαμορφώσεις στις οποίες μπορεί να είναι ευάλωτη μια εφαρμογή. Επιπλέον, προτάθηκε ένας μηχανισμός αποτροπής σε επίπεδο λειτουργικού συστήματος με όνομα TaskAuth που ελέγχει και περιορίζει την πρόσβαση των εφαρμογών σε activities. Το TaskAuth λειτουργεί με διαφάνεια τόσο για τους χρήστες όσο και για τους προγραμματιστές καθώς αξιοποιεί τις ενσωματωμένες υπογραφές που φέρουν οι εφαρμογές Android. Η αποτελεσματικότητα του TaskAuth αξιολογήθηκε σε σχέση με διάφορες ευάλωτες διαμορφώσεις που ανέδειξε το Anactijax και τα αποτελέσματα έδειξαν ότι η εφαρμογή της προτεινόμενης λύσης δεν επηρεάζει τη διαχείριση των tasks του Android ούτε επιβαρύνει τους χρόνους εκτέλεσης των εφαρμογών. Τέλος, εξετάζονται οι απειλές intent redirection and intent hijacking στο σύστημα Android. Αυτές οι απειλές μπορούν να επηρεάσουν την εμπιστευτικότητα και την ακεραιότητα των δεδομένων των χρηστών, καθώς κακόβουλες εφαρμογές που εκμεταλλεύονται τέτοιες ευπάθειες σε άλλες εφαρμογές μπορούν να εξαπατήσουν τους χρήστες και να αποκτήσουν πρόσβαση ή να παραποιήσουν τα δεδομένα τους. Έτσι, μελετήθηκαν διεξοδικά οι απειλές intent redirection and intent hijacking και για την αποτροπή τους προτάθηκε ένας μηχανισμός προστασίας των χρηστών σε επίπεδο λειτουργικού συστήματος με όνομα IntentAuth που δίνει τη δυνατότητα στους χρήστες να καθορίζουν δυναμικές πολιτικές στα σύνολα των εφαρμογών που επιτρέπουν να αλληλοεπιδρούν μεταξύ τους. Επιπλέον, βάσει του μοντέλου εμπιστοσύνης που ο κάθε χρήστης καθορίζει για τις εγκατεστημένες εφαρμογές του, ο μηχανισμός IntentAuth μπορεί να κρυπτογραφήσει τα μεταδιδόμενα δεδομένα της διαδιεργασιακής επικοινωνίας του συστήματος μεταξύ εφαρμογών με implicit intents χωρίς επιβάρυνση του χρόνου εκτέλεσης.

Exploration on the Materials Quality Control of Railway Vehicle Weld Structure Based on Service Safety Demand

With the continuous increasing of service-rail-vehicle in China, some defects such as cracks appeared at different stages of service when they had not reached the design life, while current theories and methods cannot explain the appearance of defects, which brought risks and hidden dangers to the operation of the vehicles. It was found that the reasons were mainly caused by one or several factors such as material performances, design, manufacturing process and operating environment. Since more and more sensors being installed on the vehicles to supervise the health of structure, it is more improtant to focus on the performances of materials. Through comparing different material standards including international, national, railway industry and enterprise standards, as well as the technical delivery conditions of other industries, it was recommended that the fracture mechanical parameters such as fracture toughness and fatigue crack growth should be proposed into the materials quality control regulations of original equipment manufacturers (OEMs). Furthermore, based on the testing data of materials from OEMs, several suggestions were proposed on the basic performance of materials such as raising the requirements contained impact, metallography and corrosion resistance properties in order to provide guarantee for the service safety of vehicles.

Safety related study of Expanding Pin systems application in lifting and drilling equipment within Construction, Offshore, and Marine sectors

A questionnaire-based survey has been performed among original equipment manufacturers (OEMs), sub-suppliers, engineering companies, end-users, service & maintenance, and “others”, as part of an investigation to clarify their relationship to expanding pin system, compared to standard, cylindrical pins. In addition, a short literature study on onshore cranes is conducted. The survey is based on 9 questions about safety for personnel and machine, breakage, and wear of pins and supports, and installation and retrieval easiness of pins. The analysis of the responses indicates that safety for personnel and machines/equipment is regarded mainly as either “Important” or “Crucial and decisive”, and that the expanding pin solution is regarded as “better” or “equal” compared to the standard, cylindrical pin, both for “safety level”, “risk for breakage of pin & support”, “tear & wear on pin & support” and “installation and retrieval time”.

Reliability Evaluation of Lithium-Ion Batteries for E-Mobility Applications from Practical and Technical Perspectives: A Case Study

Evaluation of the reliability of the components of electric vehicles (EVs) has been studied by international research centers, industry, and original equipment manufacturers over the last few years. Li-ion batteries are the main sensitive component of an EV’s E-power train. In other words, the Li-ion batteries for electromobility applications are one of the main components of an EV, which should be reliable and safe over the operational lifetime of the EV. Thus, investigating how to assess the reliability of the Li-ion battery has been a highly recommended task in most European projects. Moreover, with the increase in the number of new EVs made by European car companies, there has been a competition for market acquisition by these companies to win over customers and gain more market share. This article presents a comprehensive overview of the evaluation of the reliability of Li-ion batteries from practical and technical perspectives. Moreover, a case study for assessing reliability from practical and technical perspectives has been investigated.

Prioritizing Roadway Pavement Marking Maintenance Using Lane Keep Assist Sensor Data

There are over four million miles of roads in the United States, and the prioritization of locations to perform maintenance activities typically relies on human inspection or semi-automated dedicated vehicles. Pavement markings are used to delineate the boundaries of the lane the vehicle is driving within. These markings are also used by original equipment manufacturers (OEM) for implementing advanced safety features such as lane keep assist (LKA) and eventually autonomous operation. However, pavement markings deteriorate over time due to the fact of weather and wear from tires and snowplow operations. Furthermore, their performance varies depending upon lighting (day/night) as well as surface conditions (wet/dry). This paper presents a case study in Indiana where over 5000 miles of interstate were driven and LKA was used to classify pavement markings. Longitudinal comparisons between 2020 and 2021 showed that the percentage of lanes with both lines detected increased from 80.2% to 92.3%. This information can be used for various applications such as developing or updating standards for pavement marking materials (infrastructure), quantifying performance measures that can be used by automotive OEMs to warn drivers of potential problems with identifying pavement markings, and prioritizing agency pavement marking maintenance activities.

Employee Satisfaction, Corporate Social Responsibility and Financial Performance

This study explores the extent to which employee turnover, a proxy variable to employee loyalty, helps mediate the relationship between Taiwanese firms’ corporate social responsibility (CSR) performance and financial outcome. The results show that a firm’s CSR performance is negatively correlated with employee turnover and turnover variability, and moreover, employee turnover is negatively correlated with a firm’s financial performance. The result is especially noteworthy for studies regarding Taiwanese companies since quite a few of them are original equipment manufacturers (hereafter also referred to as OEMs), of intermediate goods. For the sample firms, although the contribution of social responsibility appears to have insignificantly direct benefit on financial performance, we document that the extent to which CSR conducts influence on long-term financial outcomes may be moderated and mediated by employee enthusiasm.

Requirements for a Product Lifecycle Management System Using Internet of Things and Big Data Analytics for Product-as-a-Service

Product-as-a-service (PaaS) offerings have advantages and potential for transforming societies to a circular economy and for improving environmental performance. Original equipment manufacturers providing PaaS offerings take higher responsibility for product performances in the use phase than those selling products. This responsibility can be supported by digital technologies such as the Internet of Things (IoT) and big data analytics (BDA). However, insights on how data of product designs and in-use services are managed for PaaS offerings in product lifecycle management (PLM) software are scarce. This mini-review first gives an account of extant major research works that successfully applied BDA, a specific technique of artificial intelligence (AI), to cases in industry through a systematic literature review. Then, these works are analyzed to capture requirements for a PLM system that will exploit the IoT and BDA for PaaS offerings. The captured requirements are summarized as (1) facilitate product and service integration, (2) address multiple lifecycles, (3) adopt an ontology approach encompassing several product standards, and (4) include reading data to process in an interoperation layer.

FUZZY-BASED FRAMEWORK FOR MANAGING INTER-ENTERPRISE COLLABORATIONS IN PSS CONTEXT

One of the biggest challenges of companies developing new solutions is how to properly manage the different relationships with external partners, especially in the case of Product-Service Systems (PSS). Developing a PSS requires for Original Equipment Manufacturers (OEM) to rethink the organization and roles of the different stakeholders regarding the characteristics of such environments. This paper aims to introduce a methodology to build a framework for inter-enterprise collaboration performance assessment and its corresponding Key Performance Indicators (KPIs). An extensive list of KPIs is established from key factors of collaboration performance and organizational characteristics in PSS context. Finally, further steps of the methodology are discussed where fuzzy techniques are used.

Recentralizing Industrial Relations? Local Unions and the Politics of Insourcing in Three North American Automakers

Since the auto industry’s 2008 crisis, the decades-long trend toward outsourcing by the Detroit Three automakers has stalled. During and after the crisis, original equipment manufacturers moved work inside their corporate boundaries, including the purchase of eight previously spun-off parts plants. Why has this happened? Drawing on 77 interviews in the United States and Canada and 27 insourcing cases, the authors explore how and why insourcing has taken place. Past literature has considered the costs and benefits of creating the vertically integrated corporation, the managerial politics behind vertical disintegration, and the labor–management relations that shape both. While much industrial relations scholarship points to decentralized plant-level partnerships as a union strategy to win investment, the authors find that local unionists are intervening in the politics of the corporation above the plant level to influence the purchasing, manufacturing, and engineering functions that determine the sourcing decision.