Charge‐recombination processes in oligomer‐ and polymer‐based light‐emitting diodes: A molecular picture

Abstract— An overview of our recent work on the mechanisms of singlet and triplet exciton formation in electroluminescent π‐conjugated materials will be presented. According to simple spin statistics, only one‐fourth of the excitons are formed as singlets. However, deviations from that statistics can occur if the initially formed triplet charge‐transfer (CT) excited states are amenable to intersystem crossing or dissociation. Although the electronic couplings between the CT states and the neutral exciton states are expected to be largest for the lowest singlet and triplet excitons (S¹ and T¹, respectively), the possibility for direct recombination into T¹ is always very small due to the large exchange energy. In small molecules, spin statistics is expected to be observed because both singlet and triplet exciton formations proceed via higher‐lying S_n/T_n states with similar electronic couplings and fast formation rates. In extended conjugated chains, however, that the ¹CT → S¹ pathway is faster while the ³CT → ^Tn channels become much slower, opening the route to intersystem crossing or dissociation among the ³CT states.     

A finite volume–finite difference method with a stiff ordinary differential equation solver for advection–diffusion–reaction equation

A model for atmospheric pollutant transport is proposed considering an advection–diffusion–reaction equation. A splitting method is used to decouple the advection, diffusion and reaction parts. A scheme based on finite volume, finite difference and backward differentiation formula is used for solving an atmospheric transport-chemistry problem.     

A reliability based maintenance policy; a case study

Reliability centered maintenance (RCM) incorporates sound guidance for managers who wish to attain high standards of maintenance at their operating plants. Since the amount and type of maintenance which is applied depend strongly on the machine or components age (DFR, CFR or IFR), on its replacement cost as well as on the cost and safety consequences of system failure, a careful analysis of the system components based on their reliability data should be done in order to optimize the maintenance program. This paper describes the methodology which was used at an aluminum plant in order to select critical machines and to develop an optimal maintenance policy based on reliability data of each machine, safety consequences of system failure, lead time and repair time, and components criticality.     

Versatile Tuning of Humanoid Agent Activity

In this paper, we present an integration framework for heterogeneous motion generators. The objective is to outline issues that are currently easily solved in professional post-processing systems used in film and game production but which cannot be transposed as is to real-time systems with autonomous agents. We summarise our approach for articulated agent-modelling and their animation by combining heterogeneous motion generators, such as real-time motion capturing, key-framing, inverse kinematics, procedural walking. We propose an agent/action-oriented framework. Activity properties such as action simultaneity and motion blending, spatial coherence, motion-flow update schemes, agent attachments, and location corrections, are the main topics handled by our generic animation framework. Numerous examples throughout the paper illustrate our approach and outline encountered problems and solutions or open research directions.     

Modeling multi-rate DSP specification semantics for formal transformational design in HOL

The CATHEDRAL Silicon Compilers synthesize hardware for DSP algorithms specified in Silage, a high level applicative language. In order to optimize the results of the silicon compilation in terms of chip-area and/or throughput, the user often massages the specification applying transformations to the Silage code. To guarantee that the transformations preserve the behavior of the specified algorithm, the formal semantics of the specification language had to be defined. The semantics has been used to prove in HOL the correctness of the transformations and to prove properties of the specification. We are currently building a system where a menu of useful andcorrectness preserving transformations will be available to the user. In this system the user could choose appropriate transformations from the menu taking advantage of his creativity and expertise to interactively guide the silicon compiler, without the risk of introducing inconsistencies. This article describes the formalmulti-rate semantics of a substantial subset of Silage and illustrates some formally verified transformations.     

Influence of material handling devices on the physical load during the end assembly of cars

The effect of using a mechanical device on physical load was analysed during the end assembly of cars. Five tasks, further sub-divided into lifting and positioning, were performed by someone experienced in working with and without the mechanical tool. A practical methodology was used: the subjective walk and talk through method, the NIOSH equation (1991), a three-dimensional goniometer (Back Tracker) and surface electromyography (EMG) of the relevant muscle groups. According to the NIOSH equation, 8 out of 10 of the tasks should only be performed by trained workers and preferably with tools. The Back Tracker revealed that the mechanical tools reduced posture angles significantly (p0.05) for installing the windows, but not for left lateroflexion during pre-assembly of windows. It was clear from the EMG analysis that using tools did not always decrease muscular activity significantly. In general, the appropriateness of each tool needs to be evaluated separately taking the subjective criteria into account.

Relevance to industry

In this study, the relevance of using a mechanical device to reduce the physical load during car assembly, is evaluated. As the tools are expensive, it is important to the industry whether they are being used and how efficient they are.     

On‐the‐job Innovation: The Impact of Job Design and Human Resource Management through Production Ownership

A growing number of practitioners and academics endorse that the ability of organizations to foster, develop and use the innovative potential of their employees contributes to organizational success. Yet empirical investigation of individual innovation processes is lacking. In this research we address the question of whether both more flexibility in an employees’ job design and commitment‐oriented HRM activities promote individual innovative work behaviour. Findings suggest that a multifunctional job design and the perceived HRM system promote employee involvement in innovative activities through increased feelings of ownership for work‐related issues and problems.     

Outlier Detection under Interval Uncertainty: Algorithmic Solvability and Computational Complexity

In many application areas,it is important to detect outliers. The traditional engineering approach to outlier detection is that we start with some normal values x₁, ...,x_n, compute the sample average E, the sample standard variation , and then mark a value x as an outlier if x is outside the k₀-sigma interval [E – k₀ , E + k₀ ] (for some pre-selected parameter k₀).In real life,we often have only interval ranges [ ] for the normal values x₁, ...,x_n. In this case,we only have intervals of possible values for the bounds and . We can therefore identify outliers as values that are outside all k₀-sigma intervals.Once we identify a value as an outlier for a fixed k₀, it is also desirable to find out to what degree this value is an outlier, i.e., what is the largest value k₀ for which this value is an outlier.In this paper,we analyze the computational complexity of these outlier detection problems, provide efficient algorithms that solve some of these problems (under reasonable conditions), and list related open problems.     

Deep Expectation of Real and Apparent Age from a Single Image Without Facial Landmarks

In this paper we propose a deep learning solution to age estimation from a single face image without the use of facial landmarks and introduce the IMDB-WIKI dataset, the largest public dataset of face images with age and gender labels. If the real age estimation research spans over decades, the study of apparent age estimation or the age as perceived by other humans from a face image is a recent endeavor. We tackle both tasks with our convolutional neural networks (CNNs) of VGG-16 architecture which are pre-trained on ImageNet for image classification. We pose the age estimation problem as a deep classification problem followed by a softmax expected value refinement. The key factors of our solution are: deep learned models from large data, robust face alignment, and expected value formulation for age regression. We validate our methods on standard benchmarks and achieve state-of-the-art results for both real and apparent age estimation.