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Power system voltage security assessment is generally applied by considering the power system loadability surface. For a large power system, the loadability surface is a complicated hyper-surface in parameter space, and local approximations are a necessity for any analysis. Unfortunately, inequality constraints due to for example generator overexitation limiters, and higher codimension bifurcation
Landscapes influence precipitation via the water vapor and energy fluxes they generate. Biologically active landscapes also generate aerosols containing microorganisms, some being capable of catalyzing ice formation and crystal growth in clouds at temperatures near 0 degrees C. The resulting precipitation is beneficial for the growth of plants and microorganisms. Mounting evidence from observation
In this paper, we consider 3D wave-packet transform that is useful in 3D data processing. This transform is computationally intensive even though it has a computational complexity of O(N3 log N). Here we present its implementation on GPUs using NVIDIA CUDA technology. The code was tested on different types of graphical processors achieving the average speedup up to 46 times on Tesla M2050 compared
Entrained flow gasification is a promising technique where biomass is converted to a synthesis gas (syngas) under fuel-rich conditions. In contrast to combustion, where the fuel is converted to heat, CO2, and H2O, the syngas from gasification is rich in energetic gases such as CO and H-2. These compounds (CO and H-2) represent the building blocks for further catalytic synthesis to chemicals or bio
Urban areas adjacent to surface water are exposed to soil movements such as erosion and slope failures (landslides). A landslide is a potential mechanism for mobilisation and spreading of pollutants. This mechanism is in general not included in environmental risk assessments for contaminated sites, and the consequences associated with contamination in the soil are typically not considered in lands
Lately, much work in the area of voltage stability assessment has been focused on finding post-contingency corrective controls. In this article a contribution to this area will be presented where we search for maximal loadability while considering post-contingency corrective controls. This objective is different from the usual approach to the problem, where the aim is to include the post-contingen
We consider the least-squares (L2) minimization problems in multiple view geometry for triangulation, homography, camera resectioning and structure-and-motion with known rotatation, or known plane. Although optimal algorithms have been given for these problems under an Linfinity cost function, finding optimal least-squares solutions to these problems is difficult, since the cost functions are not
Abstract in UndeterminedThe separation of global radiation (Rg) into its direct (Rb) and diffuse constituents (Rg) is important when modeling plant photosynthesis because a high Rd:Rg ratio has been shown to enhance Gross Primary Production (GPP). To include this effect in vegetation models, the plant canopy must be separated into sunlit and shaded leaves. However, because such models are often to
As automatic sensing and information and communication technology get cheaper, building monitoring data becomes easier to obtain. The availability of data leads to new opportunities in the context of energy efficiency in buildings. This paper describes the development and validation of a data-driven grey-box modelling toolbox for buildings. The Python toolbox is based on a Modelica library with th
We present the open-source software framework in JModelica.org for numerically solving large-scale dynamic optimization problems. The framework solves problems whose dynamic systems are described in Modelica, an open modeling language supported by several different tools. The framework implements a numerical method based on direct local collocation, of which the details are presented. The implemen
Due to the possibility of increased efficiency and reduced emissions, Homogeneous Charge Compression Ignition (HCCI) is a promising alternative to conventional internal combustion engines. Ignition timing in HCCI is highly sensitive to operating conditions and lacks direct actuation, making it a challenging subject for closed-loop control. This paper presents physics-based, control-oriented modeli
We consider the problem of gray-box identification of dynamic models for mechanical systems. In particular, the problem is approached by means of continuous-time system identification using subspace-based methods based on discrete-time input-output identification data. A method is developed, with the property that the structure of the model resulting from fundamental physical first principles is o
Abstract in UndeterminedMinimum distances and maximum likelihood error probabilities of serial turbo codes with uniform interleaver are analyzed. It is shown that, for a fraction of interleavers approaching one as the block-length grows large, the minimum distance of serial turbo codes grows as a positive power of their block-length, while their error probability decreases exponentially fast in so
Industrial robots are usually programmed to follow desired trajectories, and are very good at position-controlled tasks. New applications, however, often require physical contact between the robot and its environment, and then the position control accuracy is generally not sufficient. Force control is a suitable alternative. The environment is often stiff, and then it is crucial to design appropri
A major challenge for a person with diabetes is to adapt insulin dosage regimens and food intake to keep blood glucose within tolerable limits during daily life activities. The early knowledge about the effects of inputs on glycemia would provide the patients with invaluable information for appropriate on-the-spot decision making concerning the management of the disease. Against this background, i
Mapping coastal inlets and their catchment areas is essential for management of the coastal zone. The coastal inlets are important channels of exchange of nutrients, water and sediment between the land and sea. They are also important elements of the coastal hydrological system and play a vital role in controlling the water flow into the sea during floods. Blocking of the coastal inlets is one of
Abstract in UndeterminedRobustness of distributed routing policies is studied for dynamical networks, with respect to adversarial disturbances that reduce the link flow capacities. A dynamical network is modeled as a system of ordinary differential equations derived from mass conservation laws on a directed acyclic graph with a single origin-destination pair and a constant total outflow at the ori
