1,636 research outputs found
Comprehensive Social Contribution Oriented Resources Optimization Model for Higher Education
In light of the shortage of the higher education resource, the optimal allocation of higher education resources is investigated in this paper. The optimization model of higher education resources is designed based on the comprehensive contribution of higher education in such aspects as economy, science and technology, and society. The solution of the model can be achieved by our proposed resources allocation algorithm based on particle swarm. By optimizing the allocation of higher education resources, the capability of social contribution of higher education is improved, and a reference scheme is provided to make efficient and reasonable use of limited resources of higher education. Key words: Higher education; Social contribution; Resources allocation; Particle swar
Study on Unconventional Emergency Scenario Design: Taking Life-Rescuing of Dongfang Turbine Co., Ltd. in Wenchuan Earthquake for Example
Unconventional emergencies have attracted widespread concern in academic field due to its high uncertainty, huge destructiveness and complex management, and studies on unconventional emergencies shall change from “prediction-response” to “scenario-response”. By taking the life-rescuing of Dongfang Turbine Co., Ltd. in Wenchuan Earthquake for example, this paper divides scenarios in accordance with the specific investigations, and proposes several considerations about the unconventional emergency scenario study
Managing in conflict: how actors collaborate in marketing green chemistry
The purpose of this research is to investigate business relationships, by drawing on conflict theories from organization studies and taking a mid-range research perspective to further develop these into industrial marketing research. IMP researchers have examined conflict as a threat to established business relationships and commercial exchanges, drawing on theories and concepts developed in organization studies. I adopt the behavioural approach from organisation studies, and contracts with particularly the socio-psychological approaches relating to the affective emotions of small groups. I find that there is much in common between the definitions of conflict developed by March (1999) and the theories of Jehn and Mannix (2001) on the combination of affective and cognitive ways of undertaking activities in conflicts, as conflict as experienced, emotional, aligned with material entities. These approaches have had a great influence but have not been fully considered in business-to-business research. This thesis aims to investigate how actors manage, and manage in, conflicts, and how their relationships dynamics work within networks. I develop conflict research by drawing on the IMP and Market Studies approaches, which address the pervasive conditions of business activity, encompassing the relationships and resources experienced by actors as events which trigger emotions.
The overall research method chosen for this research is the case study. I identify five cases of relationships from the oil and gas industry’s service sector and examine conflict, its emotional dimensions and actors’ activities in conflicts within these cases in three empirical study chapters. Study 1 examines conflict of interest and resources and conflict as experienced by actors. Study 2 examines conflict from the emotional perspective by investigating a series of events and event-triggered emotions across the five cases of relationships. Study 3 focuses on adaptive activities undertaken in conditions of pervasive conflict, which produce incremental innovation.
I propose an explanation of how actors manage, and manage in, conflict given that they tend to value and maintain relationships beyond individual episodes of exchange. Conflicts are investigated in relationships from a network perspective, showing that actors experienced these while adapting to changes in their business setting (regulation, technology or/and cost), modifying their roles in that network. By identifying conflict with the organizing forms of relationships and networks, the research shows how actors handle conflict by pursuing and combining a number of strategies, distributing the conflict across an enlarged network. By investigating the emotional dimension of conflicts, I find that affective emotion effects relationships and relationship dynamics. Actors transform and resource emotions with material entities, and in this process markets are shaped. Adaptations are part of the normal activities; actors, driven by medium term Chemical Management Service (CMS) contracts and cost pressures, undertake incremental innovation. An incremental innovation model is designed to illustrate the process of incremental innovation that operates for the ‘green chemical’ industry, and guides actors to contain costs through managing portfolios and resources, forecasting and innovation agenda, and reducing uncertainties in networks
Processing and Patterning of Conducting Polymer Films for Flexible, Stretchable and Healable Electronics
L'électronique flexible, étirable et autoréparante a le potentiel de redéfinir l'apparence, la conception et la fabrication des appareils électroniques ayant un impact sur l'électronique personnelle, la peau électronique et les soins de santé. Le développement de l'électronique flexible, étirable et autoréparante à des fins biologiques et médicales fait appel à la biocompatibilité et la transparence des matériaux électroniques adaptable. Parmi ces matériaux, les polymères organiques conducteurs présentent des opportunités uniques. La recherche sur les propriétés électroniques, chimiques et mécaniques des polymères organiques conducteurs permet d’assurer leur intégration dans les appareils électroniques adaptable.
Cette thèse explore le traitement des polymères organiques conducteurs et le développement de nouvelles technologies de fabrication pour l'électronique flexible, étirable et autoréparante.
Nous avons premièrement recherché les effets de plusieurs additifs sur les propriétés fondamentales du polymère conducteur poly(3,4-éthylènedioxythiophène) polystyrène sulfonât (PEDOT:PSS). Nous avons démontré que les additifs jouent des rôles vitaux dans la détermination de la conductivité électronique de la couche mince, les propriétés mécaniques et la stabilité dans l'eau (essentielle aux applications biologiques). Nous avons trouvé que les couches minces déposées sur des substrats flexibles en plastiques ou sur des élastomères étirables démontrent une stabilité accrue dans l'eau en comparaison avec les couches minces sur des substrats rigides en verre. Des couches minces de PEDOT:PSS hautement conductrices, étirables et stables dans l'eau ont été obtenues en ajustant la composition chimique des couches et en contrôlant les conditions de traitement.
Pour la fabrication de dispositifs flexibles et étirables, un défi majeur apparait lors de la génération de patron de matériaux électroniques organiques dans le but de produire une électronique à haute résolution. L'application de la photolithograpie à cet effet n'est pas aussi facile, car les composés chimiques utilisés dans cette technique (photorésines, développeurs, décapant de résine) peuvent contaminer ou solubiliser les polymères organiques conducteurs. De plus, la génération de patrons d’électrodes métalliques pour les électroniques souples crée aussi un défi. En effet, l'adhésion des photorésines sur la surface des substrats souples (tels que les élastomères) sur lesquels les composants électroniques sont déposés est faible.
Nous avons pu fabriquer, avec une résolution micrométrique, des dispositifs qui peuvent soutenir des plis et des extensions afin de leur permettre de s'adapter à des surfaces courbées, souples et élastiques. À cet effet, nous avons utilisé une photorésine récemment développée, qui est immiscible avec des matériaux organiques, pour générer des patrons de PEDOT:PSS. Des masques basés sur des couches minces (2 µm) de polymère ont été utilisées pour générer des patrons d’électrodes métalliques.
Ensuite, nous avons utilisé ces techniques pour fabriquer des transistors électrochimiques flexibles et étirables avec une résolution micrométrique. Nos dispositifs ont démontré une haute performance sous des conditions de pli et d'étirement et aussi une très bonne stabilité cyclique.
Les dispositifs électroniques souples doivent supporter la déformation mécanique à travers le temps, qui peut endommager les appareils et nuire à leur fonctionnalité. Le développement de matériaux autoréparants, pouvant restaurer la fonctionnalité de l'appareil après endommagement, permettrait d’améliorer grandement la longévité de l'électronique souple. En particulier, l’autoréparation des matériaux électroniques organiques est de première importance car elle peut être combinée avec la flexibilité et la biocompatibilité. Ainsi, cette propriété est très prometteuse pour la détection biologique, l'enregistrement neurologique et l’ingénierie tissulaire.
Nous avons exploré les propriétés d’autoréparation du PEDOT:PSS. Les couches de PEDOT:PSS, avec une épaisseur de plus de 1 µm, démontrent une autoréparation électronique instantanée après que de l'eau ait été appliquée à l'endroit endommagé. Le processus d’autoréparation des couches minces n'est pas affecté par le dommage répété et se réalise très rapidement après mouillage. L’autoréparation se fait même après exposition à la vapeur d'eau. Nous avons établi qu’une application possible pour les couches minces autoréparantes est de les utiliser dans des détecteurs d’eau ultrasensibles.
La fabrication avancée et les techniques de traitements étudiées dans cette thèse permettront de paver la voie pour le développement de microélectroniques organiques souples pour les appareils électroniques portatifs et de stockage d'énergie flexibles, les écrans flexibles et les détecteurs d'humidité. En particulier, le fait que les appareils puissent travailler de manière stable et s'auto réparer dans l'eau, mène à de futures applications dans la détection biologique, les interfaces neurales, l'administration de médicaments et l'ingénierie tissulaire.
----------ABSTRACT
Flexible, stretchable and healable electronics have the potential to redefine the appearance, design and fabrication of electronic devices, with a profound impact on personal electronics, electronic skin and healthcare. The development of flexible, stretchable and healable electronics, in particular for biological or healthcare applications, calls for biocompatible, transparent and conformable electronic materials, among which organic conducting polymers present unique opportunities. Investigation of the fundamental properties of organic conducting polymers, in order to control their electronic, chemical and mechanical properties is therefore of great importance for their integration into conformable organic electronic devices.
This thesis explores the processing of organic conducting polymer and the development of new fabrication technologies for flexible, stretchable and healable electronics.
We first investigate the effect of several additives on the fundamental properties of the conducting polymer, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). We demonstrate that the additives play vital roles in determining the films’ electronic conductivity, mechanical properties, and water stability (essential for biologic applications). We find that films on flexible plastic and stretchable elastomer substrates show enhanced water stability compared with that of films on rigid glass substrates. Highly conductive, intrinsically stretchable and water-stable PEDOT:PSS thin films are finally obtained by adjusting the films’ chemical composition and controlling the processing conditions.
For the fabrication of flexible and stretchable device, a major challenge is the patterning of organic electronic materials to produce electronics with high resolution. Applying conventional photolithographic techniques to this purpose is not straightforward, because the standard lithography chemicals (photoresists, developers, strippers) may contaminate or solubilize the organic material. In addition, the patterning of metallic electrodes for soft electronics is also challenging because photolithography is an inefficient method for directly patterning stretchable electronics, due to the poor adhesion of the photoresist on the surfaces of soft substrates (such as elastomers) on which electronic components are deposited.
We are able to pattern devices with microscale resolution that are able to sustain not only bending but also extensive stretching, so that they can accommodate on curved, soft, and elastic surfaces. To this purpose we use a recently developed photoresist, which is non-miscible with organic materials, to pattern PEDOT:PSS and a ultrathin polymer film (< 2 µm) to pattern metallic electrode arrays on stretchable substrates. We use these technologies thereafter to develop both flexible and stretchable organic electrochemical transistors with microscale resolution. Our devices show high performance with unchanged electrical properties under extreme bending or stretching conditions, and also superior cyclic stabilities.
Soft electronics must endure mechanical deformation over time, which may damage devices and disable their functionality. The development of healable materials, which can repair themselves and restore the device functionality after damage could greatly improve the longevity of soft electronics. Particularly, healing of organic electronic materials is of primary importance because it can be combined with flexibility and biocompatibility, thus being very promising for long-term biological sensing, neurologic recording and tissue engineering applications.
We explore the healing property of PEDOT:PSS. PEDOT:PSS films (with thickness greater than 1 µm) show instantaneous electronic healing after water is applied to the damaged area. The healing process of the films is not affected by repeated damage to the film and occurs very rapidly, i.e. within 150 ms after wetting. Healing occurs even after exposure to water vapor. The potential of healable PEDOT:PSS thin films is demonstrated as ultrasensitive water detectors and as active materials for self-healing organic electronic devices.
The advanced fabrication and processing technologies investigated in this thesis pave the way for the development of soft organic microelectronics for personal wearable electronics, flexible energy storage devices, flexible display and humidity detectors. In particular, the fact that devices can work stably and can self-repair in water leads to further applications in biological sensing, neural interfaces, drug delivery, and tissue engineering
Self-Supervised Transformer with Domain Adaptive Reconstruction for General Face Forgery Video Detection
Face forgery videos have caused severe social public concern, and various
detectors have been proposed recently. However, most of them are trained in a
supervised manner with limited generalization when detecting videos from
different forgery methods or real source videos. To tackle this issue, we
explore to take full advantage of the difference between real and forgery
videos by only exploring the common representation of real face videos. In this
paper, a Self-supervised Transformer cooperating with Contrastive and
Reconstruction learning (CoReST) is proposed, which is first pre-trained only
on real face videos in a self-supervised manner, and then fine-tuned a linear
head on specific face forgery video datasets. Two specific auxiliary tasks
incorporated contrastive and reconstruction learning are designed to enhance
the representation learning. Furthermore, a Domain Adaptive Reconstruction
(DAR) module is introduced to bridge the gap between different forgery domains
by reconstructing on unlabeled target videos when fine-tuning. Extensive
experiments on public datasets demonstrate that our proposed method performs
even better than the state-of-the-art supervised competitors with impressive
generalization
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