33 rd CDC Abstract. This paper brings together results from a number of diier-ent areas in control theory to provide an algorithm for the synthesis of locally exponentially stabilizing control laws for a large class of driftless nonlinear control systems. The exponential stabilization relies on the use of feedbacks which render the closed loop vector eld homogeneous with respect to a dilation. ...

This paper presents an algorithmic design for opinion extractor from free-form course feedback texts. An unsupervised lexicon-based based algorithmic formulation is designed and implemented for identifying opinion polarity from free-form textual feedbacks written by students. The performance of the algorithm is evaluated on two different course feedback datasets obtained from ratemyprofessor we...

I report the discovery of a low frequency temperature oscillation in the eastern North Atlantic (NA), which was signi®cantly correlated with the Southern Oscillation Index (SOI) in the tropical Paci®c, but led the latter index by a number of months. This discovery is signi®cant, because it demonstrates a link between the tropical Paci®c and the high northerly latitudes which cannot readily be e...

While it is true that the physical principles and equations discussed in part one do form the “core” of any atmospheric or climate model, there are processes in the observed system that are difficult to represent due to our incomplete understanding of the process, or the fact that some processes are not exact. Many of these processes are what we call “feedbacks”. Feedbacks are manifestations of...

An approach to climate change feedback analysis is described in which tropospheric relative humidity replaces specific humidity as the state variable that, along with the temperature structure, surface albedos, and clouds, controls the magnitude of the response of global mean surface temperature to a radiative forcing. Despite being simply a regrouping of terms in the feedback analysis, this al...

The authors argue for the hypothesis that interactive feedbacks involving surface enthalpy fluxes are important to the dynamics of tropical intraseasonal variability. These include cloud-radiative feedbacks as well as surface turbulent flux feedbacks; the former effectively act to transport enthalpy from the ocean to the atmosphere, as do the latter. Evidence in favor of this hypothesis include...

Content-based image retrieval and text-based image retrieval are two fundamental approaches in the field of image retrieval. The challenges related to each of these approaches, guide the researchers to use combining approaches and semi-automatic retrieval using the user interaction in the retrieval cycle. Hence, in this paper, an image retrieval system is introduced that provided two kind of qu...

[1] We extend the theory of climate feedbacks to include atmospheric chemistry. A change in temperature caused by a radiative forcing will include, in general, a contribution from the chemical change that is fed back into the climate system; likewise, the change in atmospheric burdens caused by a chemical forcing will include a contribution from the associated climate change that is fed back in...

The paper is concerned with a general optimization problem for a nonlinear control system, in the presence of a running cost and a terminal cost, with free terminal time. We prove the existence of a patchy feedback whose trajectories are all nearly optimal solutions, with pre-assigned accuracy.