61 research outputs found
Model predictive control for a thermostatic controlled system
Abstract — This paper proposes a model predictive control scheme to provide temperature set-points to thermostatic con-trolled cooling units in refrigeration systems. The control problem is formulated as a convex programming problem to minimize the overall operating cost of the system. The foodstuff temperatures are estimated by reduced order observers and evaporation temperature is regulated by an algorithmic suction pressure control scheme. The method is applied to a validated simulation benchmark. The results show that even with the thermostatic control valves, there exists significant potential to reduce the operating cost. I
Natural Fractures Characterization and In Situ Stresses Inference in a Carbonate Reservoir—An Integrated Approach
In this paper, we characterized the natural fracture systems and inferred the state of in situ
stress field through an integrated study in a very complex and heterogeneous fractured carbonate
heavy oil reservoir. Relative magnitudes and orientations of the in-situ principal stresses in a naturally
fractured carbonate heavy oil field were estimated with a combination of available data (World Stress
Map, geological and geotectonic evidence, outcrop studies) and techniques (core analysis, borehole
image logs and Side View Seismic Location). The estimates made here using various tools and data
including routine core analysis and image logs are confirmatory to estimates made by theWorld Stress
Map and geotectonic facts. NE-SW and NW-SE found to be the dominant orientations for maximum
and minimum horizontal stresses in the study area. In addition, three dominant orientations were
identified for vertical and sub-vertical fractures atop the crestal region of the anticlinal structure.
Image logs found useful in recognition and delineation of natural fractures. The results implemented
in a real field development and proved practical in optimal well placement, drilling and production
practices. Such integrated studies can be instrumental in any E&P projects and related projects such
as geological CO2 sequestration site characterization
Management of Oral Lichen Planus by 980 nm Diode Laser
Introduction: Oral lichen planus (OLP) is a mucocutaneous disease with uncertain etiology. As the etiology is unknown standard treatment modalities are not available. The traditional and common treatment relies on corticosteroids whether topical or systemic. In recent years, development of lasers made a proper path to use this instrument for treatment of the diseases which are refractory to conventional treatments. Previous studies in this field used CO2, ND:YAG, Excimer and some wavelength of diode lasers for the treatment of different types of lichen planus.Case Report: In this study, we present an OLP case which is treated using 980 nm diode laser. The result was measured by visual analogue scale (VAS) and clinical assessment; as a result, symptoms including pain and soreness started to decrease within a week, and by the end of a month completely subsided; the lesion disappeared totally as well. No recurrence was observed after a month and no side-effect was reported.Conclusion: 980 nm diode laser can be successfully used for treatment of patients with OLP
Radar Voxel Fusion for 3D Object Detection
Automotive traffic scenes are complex due to the variety of possible
scenarios, objects, and weather conditions that need to be handled. In contrast
to more constrained environments, such as automated underground trains,
automotive perception systems cannot be tailored to a narrow field of specific
tasks but must handle an ever-changing environment with unforeseen events. As
currently no single sensor is able to reliably perceive all relevant activity
in the surroundings, sensor data fusion is applied to perceive as much
information as possible. Data fusion of different sensors and sensor modalities
on a low abstraction level enables the compensation of sensor weaknesses and
misdetections among the sensors before the information-rich sensor data are
compressed and thereby information is lost after a sensor-individual object
detection. This paper develops a low-level sensor fusion network for 3D object
detection, which fuses lidar, camera, and radar data. The fusion network is
trained and evaluated on the nuScenes data set. On the test set, fusion of
radar data increases the resulting AP (Average Precision) detection score by
about 5.1% in comparison to the baseline lidar network. The radar sensor fusion
proves especially beneficial in inclement conditions such as rain and night
scenes. Fusing additional camera data contributes positively only in
conjunction with the radar fusion, which shows that interdependencies of the
sensors are important for the detection result. Additionally, the paper
proposes a novel loss to handle the discontinuity of a simple yaw
representation for object detection. Our updated loss increases the detection
and orientation estimation performance for all sensor input configurations. The
code for this research has been made available on GitHub
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