Spatial Competition in Credit Markets

Using Hotelling's two-stage model of spatial competition, we develop a lending model where the equilibrium outcome may be characterized by maximal differentiation - in contrast to Hotelling's model where firms have an incentive to reduce differentiation, as long as a pure-strategy price equilibrium exists. The difference is due to the specificities of banks' activities: banks perform independent tests to assess the credit-worthiness of their loan applicants, and thereby create a nongeographic customer heterogeneity. If banks are sufficiently pessimistic about the credit-worthiness of firms, they try to minimize the risk of default by moving away from the market centerBanking competition, Hotelling, information acquisition, credit-worthiness tests

Effect of zooplankton-mediated trophic cascades on marine microbial food web components (bacteria, nanoflagellates, ciliates)

To examine the grazing effects of copepod-dominated mesozooplankton on heterotrophic microbial communities, four mesocosm experiments using gradients of zooplankton abundance were carried out at a coastal marine site. The responses of different protist groups (nanoflagellates, ciliates) and bacterioplankton in terms of abundance and additionally, for bacteria, diversity, production, and exoenzymatic activity, were monitored during 1 week of incubation. Independent of the initial experimental abiotic conditions and the dominating copepod species, zooplankton caused order-of-magnitude changes in microbial functional groups in a clear community-wide four-link trophic cascade. The strongest predatory effects were observed for protist concentrations, thus generating inverse relationships between mesozooplankton and ciliates and between ciliates and nanoplankton. Copepod grazing effects propagated even further, not only reducing the abundance, production, and hydrolytic activity of bacterioplankton but also increasing bacterial diversity. The overall strength of this trophic cascade was dampened with respect to bacterial numbers, but more pronounced with respect to bacterial diversity and activity. High predation pressure by heterotrophic nanoflagellates, realized at the highest copepod abundance, was probably the underlying mechanism for these structural changes in the bacterial assemblages. Our results thus suggest a mechanism by which changes in higher trophic levels of marine plankton indirectly affect prokaryotic assemblages and microbially mediated ecosystem functions

Situation Creator: A Pedagogical Agent Creating Learning Opportunities

Miao, Y., Hoppe, H. U., & Pinkwart, N. (2007). Situation Creator: A Pedagogical Agent Creating Learning Opportunities. In R. Luckin, K. Koedinger & J. Greer (Eds.), Proceedings of the 13th International Conference on Artificial Intelligence in Education (pp. 614-617). Amsterdam, The Netherlands: IOS Press.In a multi-user, real-time, and situation-based learning environment, the availability of enough and appropriate situations is crucial for success. In order to improve effectiveness and efficiency of learning, we develop a new type of pedagogical agent: situation creator. Such an agent intentionally creates specific situations in the shared virtual driving place according to users’ performance information. We conduct a pilot evaluation and found that the situation creators significantly increase the number of situations that a learner can expect to encounter while using the system

A Collaborative Virtual Environment for Situated Learning of Car Driving

In the view of situated learning theory, knowledge and understanding are fundamentally products of learning situations. Learning is situated and takes place by means of legitimate peripheral participation within the context of a community of practice. Based on the theory of situated learning, this article develops conceptual and technical approaches to build a web-based collaborative 3D car-driving simulation environment that requires only low computing, networking and development resources. Rather than instructing individuals on a formal, structured, intensive and programmed base, this simulation environment supports members of virtual communities of practice to perform informal, unstructured, spontaneous, collaborative, situated learning. Pilot studies conducted with the system show its partial success and demonstrate that it depends on the characteristics of specific educationally valuable learning situations whether the collaborative learning approach we propose can succeed also with smaller group sizes

A Collaborative Virtual Environment for Situated Learning of Car Driving

Miao, Y., Pinkwart, N., and Hoppe, H.U. (2006). "A Collaborative Virtual Environment for Situated Learning of Car Driving". International Journal on Advanced Technology for Learning (ATL), 3(4), 233-240.In the view of situated learning theory, knowledge and understanding are fundamentally products of learning situations. Learning is situated and takes place by means of legitimate peripheral participation within the context of a community of practice. Based on the theory of situated learning, this article develops conceptual and technical approaches to build a web-based collaborative 3D car-driving simulation environment that requires only low computing, networking and development resources. Rather than instructing individuals on a formal, structured, intensive and programmed base, this simulation environment supports members of virtual communities of practice to perform informal, unstructured, spontaneous, collaborative, situated learning. Pilot studies conducted with the system show its partial success and demonstrate that it depends on the characteristics of specific educationally valuable learning situations whether the collaborative learning approach we propose can succeed also with smaller group sizes

Agrivoltaics—The Perfect Fit for the Future of Organic Photovoltaics

Abstract This Essay presents a possible pathway for the advancement of organic photovoltaics toward broader commercial success and enlarged market size. This vision aims at broad scale applications in photovoltaic greenhouses and polytunnels, which harvest those portions of the solar spectrum that are not used or required by plants. Based on the assumptions of the Shockley–Queisser–Limit, respectively detailed balance, and the additional postulation of using no absorption in the visible part of the AM 1.5G solar spectrum a power conversion efficiency of ≈17% is theoretically predicted. The suggestion is supported by the existence of a number of organic compounds, which already exhibit a good spectral compatibility with the typical photosynthetic action spectrum of chloroplasts. It is hoped that more suitable materials development shall be triggered and fertilized as a result of this Essay.A promising path is suggested for upscaling of organic photovoltaics (OPV) toward true mass application in the form of semi‐transparent OPV embedded in polytunnels or green‐houses. Here their specific properties, that is, offering narrow band absorption in the infrared wavelength range can be used as game changer. imag

Extracting the Auditory Attention in a Dual-Speaker Scenario from EEG using a Joint CNN-LSTM Model

Human brain performs remarkably well in segregating a particular speaker from interfering ones in a multi-speaker scenario. It has been recently shown that we can quantitatively evaluate the segregation capability by modelling the relationship between the speech signals present in an auditory scene and the cortical signals of the listener measured using electroencephalography (EEG). This has opened up avenues to integrate neuro-feedback into hearing aids whereby the device can infer user's attention and enhance the attended speaker. Commonly used algorithms to infer the auditory attention are based on linear systems theory where the speech cues such as envelopes are mapped on to the EEG signals. Here, we present a joint convolutional neural network (CNN) - long short-term memory (LSTM) model to infer the auditory attention. Our joint CNN-LSTM model takes the EEG signals and the spectrogram of the multiple speakers as inputs and classifies the attention to one of the speakers. We evaluated the reliability of our neural network using three different datasets comprising of 61 subjects where, each subject undertook a dual-speaker experiment. The three datasets analysed corresponded to speech stimuli presented in three different languages namely German, Danish and Dutch. Using the proposed joint CNN-LSTM model, we obtained a median decoding accuracy of 77.2% at a trial duration of three seconds. Furthermore, we evaluated the amount of sparsity that our model can tolerate by means of magnitude pruning and found that the model can tolerate up to 50% sparsity without substantial loss of decoding accuracy.Comment: 18 pages, 6 figure

Technologies and educational activities for supporting and implementing challenge- based learning

Our Challenge-Based Learning (CBL) method can be described as a special form of problem-based learning, in which the problems are of realistic, open-ended nature. Additionally, CBL contains features of experiential and project-based learning approaches. CBL is supported by the provision of Digital Experimentation Toolkits (DExTs) which comprise materials, initial instructions, references to web resources and specific software tools. Technological challenges lie in the ease of use in accessing these data and in communicating the learners' requests and specifications to the remote sites. Within this article we describe several classroom scenarios for the usage of DexTs in schools. Examples are the calculation of the epicenter of an earthquake, the calculation of lunar heights and the definition of strategies for navigation in a maze. The activities described in this paper were conducted within the framework of our COLDEX project (Collaborative Learning and Distributed Experimentation, http://www.coldex.info).Education for the 21 st century - impact of ICT and Digital Resources ConferenceRed de Universidades con Carreras en Informática (RedUNCI

Using Network-Text Analysis to Characterise Learner Engagement in Active Video Watching

Video is becoming more and more popular as a learning medium in a variety of educational settings, ranging from flipped classrooms to MOOCs to informal learning. The prevailing educational usage of videos is based on watching prepared videos, which calls for accompanying video usage with activities to promote constructive learning. In the Active Video Watching (AVW) approach, learner engagement during video watching is induced via interactive notetaking, similar to video commenting in social video-sharing platforms. This coincides with the JuxtaLearn practice, in which student-created videos were shared on a social networking platform and commented by other students. Drawing on the experience of both AVW and JuxtaLearn, we combine and refine analysis techniques to characterise learner engagement. The approach draws on network-text analysis of learner-generated comments as a basis. This allows for capturing pedagogically relevant aspects of divergence, convergence and (dis-) continuity in textual commenting behaviour related to different learner types. The lexical-semantic analytics approach using learner-generated artefacts provides deep insights into learner engagement. This has broader application in video-based learning environments