An Arctic-Tibetan Connection on Subseasonal to Seasonal Time Scale

Recent research indicates the great potentials of springtime land surface temperature (LST) as a new source of predictability to improve the subseasonal to seasonal climate prediction. In this study, we explore the initial cause of the springtime large-scale LST in Tibetan Plateau (TP) and disentangle its close connection with the February wave activities from the Arctic region. Our Maximum Covariance Analysis show that the spring LST in TP is significantly coupled with the regional snow cover in the preceding months. The latter is further strongly coupled with the February atmospheric circulation and wave activities in mid-to-high latitudes. When the atmospheric circulation is in a combined pattern of Arctic Oscillation and West Pacific teleconnection pattern, wave trains from the Arctic can propagate and reach the TP through northern and southern pathways. This brings dynamical and moisture conditions for the TP snowfall and builds a bridge for Arctic-Tibetan connection

Overcoming the Inherent Dependency of DEA Efficiency Scores: A Bootstrap Approach

This chapter summarizes a multi-year research effort to understand the role of process performance in the overall efficiency of banks. By focusing on the process as the unit of analysis, the authors consider how technology, human resources, and most importantly, the interaction between these factors of production contribute to overall performance. The results of this paper lead to a set of recommendations to managers of financial service organizations as to the most effective approaches for designing and managing their key service delivery processes.

Collective excitations of Dirac electrons in a graphene layer with spin-orbit interaction

Coulomb screening and excitation spectra of electrons in a graphene layer with spin-orbit interaction (SOI) is studied in the random phase approximation. The SOI opens a gap between the valence and conduction bands of the semi-metal Dirac system and reshapes the bottom and top of the bands. As a result, we have observed a dramatic change in the long-wavelength dielectric function of the system. An undamped plasmon mode emerges from the inter-band electron-hole excitation continuum edge and vanishes or merges with a Landau damped mode on the edge of the intra-band electron-hole continuum. The characteristic collective excitation of the Dirac gas is recovered in a system with high carrier density or for a large wave vector

Visual Dynamics: Stochastic Future Generation via Layered Cross Convolutional Networks

We study the problem of synthesizing a number of likely future frames from a single input image. In contrast to traditional methods that have tackled this problem in a deterministic or non-parametric way, we propose to model future frames in a probabilistic manner. Our probabilistic model makes it possible for us to sample and synthesize many possible future frames from a single input image. To synthesize realistic movement of objects, we propose a novel network structure, namely a Cross Convolutional Network; this network encodes image and motion information as feature maps and convolutional kernels, respectively. In experiments, our model performs well on synthetic data, such as 2D shapes and animated game sprites, and on real-world video frames. We present analyses of the learned network representations, showing it is implicitly learning a compact encoding of object appearance and motion. We also demonstrate a few of its applications, including visual analogy-making and video extrapolation.Comment: Journal preprint of arXiv:1607.02586 (IEEE TPAMI, 2019). The first two authors contributed equally to this work. Project page: http://visualdynamics.csail.mit.ed

Service Co-Production, Customer Efficiency and Market Competition

Customers’ participation in service co-production processes has been increasing with the rapid development of self-service technologies and business models that rely on self-service as the main service delivery channel. However, little is known about how the level of participation of customers in service delivery processes influences the competition among service providers. In this paper, a game-theoretic model is developed to study the competition among service providers when selfservice is an option. The analysis of the equilibria from this model shows that, given a certain level of customer efficiency, the proportion of the service task outsourced to the customer is a decisive factor in the resulting competitive equilibria. In the long run, two extreme formats of service delivery are expected to prevail rather than any mixture of both: either complete employee service or complete self-service. In the two-firm queuing game, we find that both firms are better off when they both deliver their service through self-service. It is also shown that full-service providers dominate the market if firms providing service products featuring self-service fail to have enough market demand at a profitable price. Meanwhile, the limited ranges of customer efficiency and the price for the self-service-only product are shown to be essential conditions for the coexistence of the different types of service providers.