A Novel Approach To Measure Product Quality In Sustainable Supplier Selection

A gap remains due to the intangible and qualitative criteria used to measure product quality for supplier evaluation and selection. Improving product quality is a crucial strategy for achieving reduce, reuse, recycle, and recovery. Quality characteristics are described as functional relationships (called profiles), and with the advancements in measurement technology, high dimensional data are collected. Nonetheless, prior studies have not addressed sustainable supplier selection where a nonlinear profile characterizes the product quality. Hence, this study aims to provide a novel approach to measure product quality using the process yield index, presents multiple comparisons with the best and difference test statistics and proposes a Bonferroni correction method. This study applies a Monte Carlo simulation to find the selection power and the required number of profiles. The statistical properties are investigated, and a comparison study is performed. The results show that multiple comparisons with the best outperform the Bonferroni method regarding the sample size requirement and power, and the number of levels and profiles were found to impact the power of the statistical tests. The required number of profiles and the critical value are tabulated for decision-makers

Beyond Personalization: Research Directions in Multistakeholder Recommendation

Recommender systems are personalized information access applications; they are ubiquitous in today's online environment, and effective at finding items that meet user needs and tastes. As the reach of recommender systems has extended, it has become apparent that the single-minded focus on the user common to academic research has obscured other important aspects of recommendation outcomes. Properties such as fairness, balance, profitability, and reciprocity are not captured by typical metrics for recommender system evaluation. The concept of multistakeholder recommendation has emerged as a unifying framework for describing and understanding recommendation settings where the end user is not the sole focus. This article describes the origins of multistakeholder recommendation, and the landscape of system designs. It provides illustrative examples of current research, as well as outlining open questions and research directions for the field.Comment: 64 page

Guidelines for Statistical Testing

This document provides an introduction to statistical testing. Statistical testing of software is here defined as testing in which the test cases are produced by a random process meant to produce different test cases with the same probabilities with which they would arise in actual use of the software. Statistical testing of software has these main advantages: for the purpose of reliability assessment and product acceptance, it supports directly estimates of reliability, and thus decisions on whether the software is ready for delivery or for use in a specific system. This feature is unique to statistical testing; for the purpose of improving the software, it tends to discover defects which would cause failures with the higher frequencies before those that would cause less frequent failures, thus focusing correction efforts in the most cost-effective way and delivering better software for a given debugging effort. Statistical testing has been reported to achieve dramatic improvements; from the point of view of costs, it facilitates the automation of the test process, thus allowing more testing at acceptable cost than manual testing would allow. This document explains the basic theory underlying statistical testing and provides guidance for its application. The material is organised to facilitate use both as an introduction for software engineers who are new to this approach to testing, and as a reference source during application. Statistical testing is applicable to practically all kinds of software, so this document is not markedly specialised for space applications, though the examples are mostly space-related and the discussion of the software lifecycle is meant to apply to common practice among ESA suppliers

Hot gas welding of thermoplastic composite T-joints:Design and Development of the T-CAT2.0 Machine

The main goal of this EngD project is to design and assemble an instrumented lab-scale research set up, able to weld a skin to a stiffener in a butt-joint configuration, in a controlled manner. This set up serves as an alternative to themore conventional joining methods like mechanical fastening and adhesive bonding. Furthermore, the production technique also proposes an alternative to the co-consolidated butt-joint of GKN Fokker by local heating and shapingof the weld area instead of full co-consolidation of the structure. Three ingredients are necessary to join a laminate to a stiffener into a T-joint configuration using the proposed hot gas welding technique. Local pre-heating of thelaminates, extruding a molten filler material to the pre-heated laminates and cooling and finishing of the weld region. The system under design is meant to be used in research programs aiming at establishing a relation between the welding input parameters and mechanical performance of the T-joint.A systems engineering approach is followed to structure the design process, starting from the customer wish. Integration of double sided welding is key for the new system under design. A start and stop function is developed, force control of the weld head towards the laminates is investigated and applied, the weld head will be tested and updated for aerospace grade thermoplastic materials and an active cooling device will be installed to control the temperature in the weld region. The weld head design of previous Thermoplastic Composite Automated T-joint (T-CAT) developments will be taken as baseline in this project.The problem is decomposed and defined via the requirements, functions, functional solutions, concepts, and to be finalized by a 3D CAD design for T-CAT2.0. The main functions of the T-CAT2.0 are double sided welding,integration of a start and stop function, pressurization of the weld region, stick-slip prevention, welding the T-joint, position the specimen and transporting the weld head.Integration and verification of the components and subsystems is achieved by systematic verification experiments. The components are integrated into the subsystems and a new verification is performed, on subsystem level. The validated system experiment showed minor local design iterations are needed to complement the system under design.The first welding sequences with Carbon/PPS with 15%wt short carbon fibers and Glass/PP laminates and a 40wt% short fiber glass filler show good interdiffusion between the filament and the laminates. Besides, repeatability experiments have been performed on Glass/PP laminates and filament material, showing consistent weld geometry over the length shown by cross-sectional micrography.The main recommendations that follow from the design of T-CAT2.0 are to optimize the weld head, perform more welding sequences to identify the temperature cycle at more locations at the weld interface and to establish a relation between the welding process parameters and mechanical performance. For mechanical performance, pull-off experiments would be recommended

The Influence of media displays and image quality attributes for HDR image reproductions

High Dynamic Range (HDR) photography has been in existence at least since the time of Ansel Adams, with his experiments using analog film and darkroom techniques for the production of black and white prints in the 1940\u27s (Ashbrook, 2010). This photographic method has the ability to provide a more accurate representation of a scene through a greater range of the light and dark areas captured in an image. In the mid-20th century HDR Photography it has continued to grow in popularity among those interested in photography wishing to optimize their resulting image beyond a more commonly used technique. Presently, the limitations of commonly available reproduction technologies can lead to unpredictable output results through media such as monitor displays and inkjet prints. The purpose of this research was to determine the influence of quality attributes and image content on the preference of display media for HDR image reproductions. To achieve this purpose, a psychophysical experiment was conducted of 38 observers with previous imaging related exposure. This part of the study consisted of HDR comparisons across both a monitor display device and inkjet prints. Through qualitative and quantitative methods, common trends were identified among observer responses. The results show that for inkjet prints are the most preferred for the output of HDR images, specifically when printed on a metallic substrate. Additionally, the content of displayed images can directly impact display preference depending on the viewer\u27s perception and relationship formed with the photographic image. When evaluating HDR images across two media platforms, quality attributes comprising of a strong influence towards preference are sharpness, naturalness, contrast and highlights while artifacts, physical qualities and shadows were found to have barely any influence. Within the attributes related to HDR, relationships between attributes are found to be significant regarding image evaluation, leading to areas of further research

Changing innovation systems in the developing country context: technology transfer and the new technological capabilities in the materials industry in Turkey

This thesis is concerned with analysing the extent that technology transfer contributes to the improvement and development of technological capabilities through learning at the firm level in a developing country context, and the impact of this process on the emergence and changes of key characteristics of innovation systems. Therefore, it investigates how innovation systems change over time and how they were influenced by technology transfer activities in the materials industry in Turkey between 1967 and 2001. As a contribution to the theory, the concept of technological capability is used as a bridge from the notion of technology transfer to that of the innovation system. Innovation system studies tend to rely on R&D statistics via innovation surveys for empirical analyses, whereas these could well be defined by qualitative data collected on technological capabilities through interviews. This thesis follows the latter route within an analytical framework that is designed for a firm-centred analysis. The qualitative data obtained from the interviews were transformed into categorical quantitative data to be used in multinomial logistic regression and linear regression analyses. This thesis shows firstly that firm-level capabilities were increasing over time during the period from 1967 to 2001 in the materials industry in Turkey. They were also increasing over time with the rising level of technological capabilities in the firms and the firms’ involvement in both collaborative relationships and in-house activities. Secondly, firmlevel capabilities shape the way the interactions in the innovation system change. As their level of technological capabilities deepen, firm interactions increase and shift to a moderate degree in plausible directions towards domestic agents, which are predominantly universities and research institutes. These findings support the firmdriven nature of the innovation systems

Collaborative Models for Supply Networks Coordination and Healthcare Consolidation

This work discusses the collaboration framework among different members of two complex systems: supply networks and consolidated healthcare systems. Although existing literature advocates the notion of strategic partnership/cooperation in both supply networks and healthcare systems, there is a dearth of studies quantitatively analyzing the scope of cooperation among the members and its benefit on the global performance. Hence, the first part of this dissertation discusses about two-echelon supply networks and studies the coordination of buyers and suppliers for multi-period procurement process. Viewing the issue from the same angel, the second part studies the coordination framework of hospitals for consolidated healthcare service delivery. Realizing the dynamic nature of information flow and the conflicting objectives of members in supply networks, a two-tier coordination mechanism among buyers and suppliers is modeled. The process begins with the intelligent matching of buyers and suppliers based on the similarity of users profiles. Then, a coordination mechanism for long-term agreements among buyers and suppliers is proposed. The proposed mechanism introduces the importance of strategic buyers for suppliers in modeling and decision making process. To enhance the network utilization, we examine a further collaboration among suppliers where cooperation incurs both cost and benefit. Coalitional game theory is utilized to model suppliers\u27 coalition formation. The efficiency of the proposed approaches is evaluated through simulation studies. We then revisit the common issue, the co-existence of partnership and conflict objectives of members, for consolidated healthcare systems and study the coordination of hospitals such that there is a central referral system to facilitate patients transfer. We consider three main players including physicians, hospitals managers, and the referral system. As a consequence, the interaction within these players will shape the coordinating scheme to improve the overall system performance. To come up with the incentive scheme for physicians and aligning hospitals activities, we define a multi-objective mathematical model and obtain optimal transfer pattern. Using optimal solutions as a baseline, a cooperative game between physicians and the central referral system is defined to coordinate decisions toward system optimality. The efficiency of the proposed approach is examined via a case study

Large-area flexible printed circuits for automotive applications

To meet the demands for safety and passenger comfort, modem passenger cars offer more and increasingly sophisticated electrical and electronic systems. The wiring harnesses that support such systems become too large, complex and heavy, when designed for a conventional electrical architecture based on 14 volts, posing several challenges to automotive manufacturers. Alternative electrical architectures based on 42 volts and in-vehicle multiplexing promise to reduce the size and weight of the wiring harness, but these architectures are yet to be fully developed and standardized. In the near term, alternative wiring solutions have gained the interest of automotive manufacturers. Small flexible printed circuits (FPCs) have previously been integrated into automotive instrument clusters. The benefits of reduced weight and space requirements of such FPCs compared to a wire harness has fuelled an interest in much larger FPCs as substitutes for the Instrument Panel and door harnesses in high-volume production cars. This research investigates the materials typically used in FPC manufacture, for applicability within a passenger car. [Continues.

Moral Hazard

"The owner of an enterprise wants to put it in the hands of a manager. The profits of the enterprise will depend both on the actions of the manager as well as the environment within which he operates. The owner cannot directly monitor the agent's action nor can he costlessly observe all relevant aspects of the environment. This situation may also last a number of successive periods. The owner and the manager will have to agree on how the manager is to be compensated, and the owner wants to pick a compensation mechanism that will motivate the manager to provide a good return on the owner's investment, net of the payments to the manager. This is the well-known "principal-agent" problem with moral hazard. Some other principal-agent relationships in economic life are: client-lawyer, customer-supplier, insurer-insured and regulator-public utility.