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Суббота, Анатолий Максимович, und Елена Юрьевна Костерная. „КІНЕМАТИКА РУХУ РОБОТА З ТРЬОМА РОЛИКОНЕСУЧИМИ КОЛЕСАМИ“. Open Information and Computer Integrated Technologies, Nr. 82 (19.12.2018): 60–71. http://dx.doi.org/10.32620/oikit.2018.82.05.
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The article introduction provides an overview of the historical development of mechatronic devices, from ancient times to the present. It is emphasized that the development of modern robotics in relation to work in aggressive environments is a very urgent task. Especially important is the creation of autonomous functioning robots to work in high radiation areas, chemically contaminated areas, demining, fire extinguishing, etc. Then this article presents material on the physics of a mechanical system motion, which is a mobile platform with three roller-bearing wheels, or so-called omni-wheels. This question is revealed on the basis of the derivation of the kinematic equations for the platform motion, based on transformation matrices, which allow to obtain the total dependences of the projections of the linear velocities of the roller-bearing wheels on the axis of the fixed (base) coordinate system. It is indicated that the transition to movement from the position at to the position at can be carried out in two ways. In the first method, the robot turns around on the center of mass by creating a torque about the vertical axis of the robot, followed by movement parallel to the axis . In the second method, by creating such a state of the wheels, i.e. the magnitude of the linear velocity and its direction, which will ensure a linear movement of the center of mass of the robot in a given direction without first rotating the body about the vertical axis. It is noted that the first method in relation to the second has both advantages and disadvantages. The advantages include ease of management and the ability to rigidly fix the camera of the review on the platform body. However, this method is more energy consuming and requires additional time for the implementation of the camera turn to a given direction. The second method is not deprived of these drawbacks, and the overview camera may have a turning mechanism, which ensures its independent functioning from the platform position control system. Given this, the kinematics of the movement of the platform according to the second method are considered. As an example, it is shown that by jointly solving the obtained kinematic equations, for example, for selected mutually perpendicular directions of the platform mass center movement, characterized by angles or , it is easy to explain the physics of platform moving in a given direction from any starting position without first turning to a given direction.
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Strauss, R., S. Schuster und K. G. Götz. „Processing of artificial visual feedback in the walking fruit fly Drosophila melanogaster.“ Journal of Experimental Biology 200, Nr. 9 (01.05.1997): 1281–96. http://dx.doi.org/10.1242/jeb.200.9.1281.
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A computerized 360 degrees panorama allowed us to suppress most of the locomotion-induced visual feedback of a freely walking fly without neutralizing its mechanosensory system ('virtual open-loop' conditions). This novel paradigm achieves control over the fly's visual input by continuously evaluating its actual position and orientation. In experiments with natural visual feedback (closed-loop conditions), the optomotor turning induced by horizontal pattern motion in freely walking Drosophila melanogaster increased with the contrast and brightness of the stimulus. Conspicuously striped patterns were followed with variable speed but often without significant overall slippage. Using standard open-loop conditions in stationary walking flies and virtual open-loop or closed-loop conditions in freely walking flies, we compared horizontal turning induced by either horizontal or vertical motion of appropriately oriented rhombic figures. We found (i) that horizontal displacements and the horizontal-motion illusion induced by vertical displacements of the oblique edges of the rhombic figures elicited equivalent open-loop turning responses; (ii) that locomotion-induced visual feedback from the vertical edges of the rhombic figures in a stationary horizontal position diminished the closed-loop turning elicited by vertical displacements to only one-fifth of the response to horizontal displacements; and (iii) that virtual open-loop responses of mobile flies and open-loop responses of immobilized flies were equivalent in spite of delays of up to 0.1 s in the generation of the virtual stimulus. Horizontal compensatory turning upon vertical displacements of oblique edges is quantitatively consistent with the direction-selective summation of signals from an array of elementary motion detectors for the horizontal stimulus components within their narrow receptive fields. A compensation of the aperture-induced ambiguity can be excluded under these conditions. However, locomotion-induced visual feedback greatly diminished the horizontal-motion illusion in a freely walking fly. The illusion was used to assay the quality of open-loop simulation in the new paradigm.
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Liu, De Ping, Jie Li, Yu Feng Su und Yu Ping Wang. „Temperature Field Modeling and Thermal Deformation Analysis of Turning and Milling Machining Center“. Advanced Materials Research 189-193 (Februar 2011): 1986–90. http://dx.doi.org/10.4028/www.scientific.net/amr.189-193.1986.
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Taking the high-speed CX series vertical milling compound machining center of CX8075 produced by Anyang Xinsheng Machine Tool Co., Ltd. as example, the machine three-dimensional simplified model is established, the source of the heat and the distribution of the important hot-points are analyzed, the machine temperature field distribution is derived which lays a foundation for the thermal error compensation. Taking into account the moving part-saddle of the machining center, its mathematic model is obtained, the important hot-points are studied, the thermodynamic parameters are determined. Based on ANSYS finite element method, the steady-state temperature field and the thermal deformation of saddle are presented, the optimal design of high-speed and high-accuracy machine tool is doned and its thermal deformation analysis is realized.
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Diaconu, E. M. „Smart Lighting System“. Scientific Bulletin of Electrical Engineering Faculty 21, Nr. 1 (01.04.2021): 6–9. http://dx.doi.org/10.2478/sbeef-2021-0002.
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Abstract This paper proposes a system that allows the control of the lights in a house, building/edifice. The system can be controlled by an application that is made in MIT App Inventor for mobile devices that use Android OS(operating system). The application sends data, via Bluetooth, to the control center, the control center powers on the selected light by turning it on and setting its intensity based on the user preferences. The control center is made from an Arduino Nano programing board, the signal used for powering the lights and setting the brightness is a PWM (Pulse Width Modulation) signal. The system contains the Arduino Nano board, Bluetooth HC-05 module for communication with the mobile application and four LED’s that are used to simulate the lights.
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Zhao, Wei, Han Xu Sun, Qing Xuan Jia, Yan Heng Zhang und Tao Yu. „Mechanical Analysis of the Jumping Motion of a Spherical Robot“. Advanced Materials Research 591-593 (November 2012): 1457–60. http://dx.doi.org/10.4028/www.scientific.net/amr.591-593.1457.
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The obstacle surmounting capability of traditional spherical mobile robot is limited, especially when the spherical mobile robot comes across vertical barrier. In this paper we design a new kind of spherical mobile robot with two-mass-one-spring mechanism based on tradition spherical mobile robot. This spherical robot could not only move agility and move with the zero turning radius like traditional spherical mobile robot but also jump in three-dimensional space. In this paper we build the mathematical model of robot jumping with friction. Numeric simulations are carried out for the model using Matlab and ADAMS, we get the similar curve. These simulation results verify the validity of the mechanics model. At last we design an experimental facility, verify the model of robot jumping by experiment. Our work will be the base of model machine designing.
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Jindrich, D. L., und R. J. Full. „Many-legged maneuverability: dynamics of turning in hexapods“. Journal of Experimental Biology 202, Nr. 12 (15.06.1999): 1603–23. http://dx.doi.org/10.1242/jeb.202.12.1603.
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Remarkable similarities in the vertical plane of forward motion exist among diverse legged runners. The effect of differences in posture may be reflected instead in maneuverability occurring in the horizontal plane. The maneuver we selected was turning during rapid running by the cockroach Blaberus discoidalis, a sprawled-postured arthropod. Executing a turn successfully involves at least two requirements. The animal's mean heading (the direction of the mean velocity vector of the center of mass) must be deflected, and the animal's body must rotate to keep the body axis aligned with the heading. We used two-dimensional kinematics to estimate net forces and rotational torques, and a photoelastic technique to estimate single-leg ground-reaction forces during turning. Stride frequencies and duty factors did not differ among legs during turning. The inside legs ended their steps closer to the body than during straight-ahead running, suggesting that they contributed to turning the body. However, the inside legs did not contribute forces or torques to turning the body, but actively pushed against the turn. Legs farther from the center of rotation on the outside of the turn contributed the majority of force and torque impulse which caused the body to turn. The dynamics of turning could not be predicted from kinematic measurements alone. To interpret the single-leg forces observed during turning, we have developed a general model that relates leg force production and leg position to turning performance. The model predicts that all legs could turn the body. Front legs can contribute most effectively to turning by producing forces nearly perpendicular to the heading, whereas middle and hind legs must produce additional force parallel to the heading. The force production necessary to turn required only minor alterations in the force hexapods generate during dynamically stable, straight-ahead locomotion. A consideration of maneuverability in the horizontal plane revealed that a sprawled-postured, hexapodal body design may provide exceptional performance with simplified control.
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Sozzi, Stefania, und Marco Schieppati. „Stepping in Place While Voluntarily Turning Around Produces a Long-Lasting Posteffect Consisting in Inadvertent Turning While Stepping Eyes Closed“. Neural Plasticity 2016 (2016): 1–14. http://dx.doi.org/10.1155/2016/7123609.
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Training subjects to step in place on a rotating platform while maintaining a fixed body orientation in space produces a posteffect consisting in inadvertent turning around while stepping in place eyes closed (podokinetic after-rotation, PKAR). We tested the hypothesis that voluntary turning around while stepping in place also produces a posteffect similar to PKAR. Sixteen subjects performed 12 min of voluntary turning while stepping around their vertical axis eyes closed and 12 min of stepping in place eyes open on the center of a platform rotating at 60°/s (pretests). Then, subjects continued stepping in place eyes closed for at least 10 min (posteffect). We recorded the positions of markers fixed to head, shoulder, and feet. The posteffect of voluntary turning shared all features of PKAR. Time decay of angular velocity, stepping cadence, head acceleration, and ratio of angular velocity after to angular velocity before were similar between both protocols. Both postrotations took place inadvertently. The posteffects are possibly dependent on the repeated voluntary contraction of leg and foot intrarotating pelvic muscles that rotate the trunk over the stance foot, a synergy common to both protocols. We propose that stepping in place and voluntary turning can be a scheme ancillary to the rotating platform for training body segment coordination in patients with impairment of turning synergies of various origin.
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Aragón-Martínez, Aldo, Manuel Arias-Montiel, Esther Lugo-González und Ricardo Tapia-Herrera. „Two-finger exoskeleton with force feedback for a mobile robot teleoperation“. International Journal of Advanced Robotic Systems 17, Nr. 1 (01.01.2020): 172988141989564. http://dx.doi.org/10.1177/1729881419895648.
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In this work, the design, manufacturing, instrumentation, and application of a two-finger exoskeleton with force feedback are presented. The exoskeleton is based on remote center of motion mechanisms in order to avoid mechanical interference with the user’s fingers and is manufactured by three-dimensional printing. The developed exoskeleton is applied in a mobile robot teleoperation by mapping the finger movements in forward and turning commands for the robot. The presence of obstacles detected by the robot is sensed by the user by means of a feedback force. The problem of simultaneously communicating a data acquisition card and the robot hardware by MATLAB ® Simulink® was solved by using an external Wi-Fi module. The result is a lightweight exoskeleton which is able to communicate bidirectionally with a mobile robot by a personal computer for teleoperation tasks. The success of the system implementation is proven by a set of experiments presented in the final part of the article.
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Delgado, Raimarius, und Byoung Choi. „Network-Oriented Real-Time Embedded System Considering Synchronous Joint Space Motion for an Omnidirectional Mobile Robot“. Electronics 8, Nr. 3 (13.03.2019): 317. http://dx.doi.org/10.3390/electronics8030317.
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This paper proposes a real-time embedded system for joint space control of omnidirectional mobile robots. Actuators driving an omnidirectional mobile robot are connected in a line topology which requires synchronization to move simultaneously in translation and rotation. We employ EtherCAT, a real-time Ethernet network, to control servo controllers for the mobile robot. The first part of this study focuses on the design of a low-cost embedded system utilizing an open-source EtherCAT master. Although satisfying real-time constraints is critical, a desired trajectory on the center of the mobile robot should be decomposed into the joint space to drive the servo controllers. For the center of the robot, a convolution-based path planner and a corresponding joint space control algorithm are presented considering its physical limits. To avoid obstacles that introduce geometric constraints on the curved path, a trajectory generation algorithm considering high curvature turning points is adapted for an omnidirectional mobile robot. Tracking a high curvature path increases mathematical complexity, which requires precise synchronization between the actuators of the mobile robot. An improvement of the distributed clock—the synchronization mechanism of EtherCAT for slaves—is presented and applied to the joint controllers of the mobile robot. The local time of the EtherCAT master is dynamically adjusted according to the drift of the reference slave, which minimizes the synchronization error between each joint. Experiments are conducted on our own developed four-wheeled omnidirectional mobile robot. The experiment results confirm that the proposed system is very effective in real-time control applications for precise motion control of the robot even for tracking high curvature paths.
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Horák, Marcel, František Novotný, Michal Starý und Josef Černohorský. „New Generation of Mobile Platform of Service Robot for Motion along Vertical Walls“. Applied Mechanics and Materials 613 (August 2014): 126–31. http://dx.doi.org/10.4028/www.scientific.net/amm.613.126.
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The paper sums up results achieved during in the last few years of the development and research of service robots aiming their use for service applications on vertically oriented walls with predominantly smooth contact surfaces having minimal altitude unevenesses within the range ± 5 mm. Two robot generations are described step by step, and both of them use the same mechanical principle of the patented system of motion. The system uses the intermittent motion when positions of the robot legs and body alternate cyclically, and the appropriate gripping force of a holding-down system is realized by vacuum. As compared with the first version, the current one allows legs to move independent in part. In that way it is possible to compensate better variations of parallelism between a contact plane of the robot holding-down system and a vertical wall. Moreover, the robot is provided with a rotary unit making possible a rotation on the axis going through the robot center and being perpendicular to the contact plane, which guarantees a change in the robot orientation in the plane. As for drives, very compact rotary actuating mechanisms (servo drives) are used, having a high ratio of power parameters in relation to weight and dimensions, combined with a control based on an industrial PC.
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Tseng, Chia-Wei, Yu-Kai Huang, Fan-Hsun Tseng, Yao-Tsung Yang, Chien-Chang Liu und Li-Der Chou. „Micro Operator Design Pattern in 5G SDN/NFV Network“. Wireless Communications and Mobile Computing 2018 (10.07.2018): 1–14. http://dx.doi.org/10.1155/2018/3471610.
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The trend of 5G mobile networks is increasing with the number of users and the transmission rate. Many operators are turning to small cell and indoor coverage of telecom network service. With the emerging Software Defined Networking and Network Function Virtualization technologies, Internet Service Provider is able to deploy their networks more flexibly and dynamically. In addition to the change of the wireless mobile network deployment model, it also drives the development trend of the Micro Operator (μO). Telecom operators can provide regional network services through public buildings, shopping malls, or industrial sites. In addition, localized network services are provided and bandwidth consumption is reduced. The distributed architecture ofμO tackles computing requirements for applications, data, and services from cloud data center to edge network devices or to the micro data center ofμO. The service model ofμO is capable of reducing network latency in response to the low-latency applications for future 5G edge computing environment. This paper addresses the design pattern of 5G micro operator and proposes a Decision Tree Based Flow Redirection (DTBFR) mechanism to redirect the traffic flows to neighbor service nodes. The DTBFR mechanism allows differentμOs to share network resources and speed up the development of edge computing in the future.
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Bluestein, Howard B., Christopher C. Weiss, Michael M. French, Eric M. Holthaus, Robin L. Tanamachi, Stephen Frasier und Andrew L. Pazmany. „The Structure of Tornadoes near Attica, Kansas, on 12 May 2004: High-Resolution, Mobile, Doppler Radar Observations“. Monthly Weather Review 135, Nr. 2 (01.02.2007): 475–506. http://dx.doi.org/10.1175/mwr3295.1.
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Abstract The University of Massachusetts W- and X-band, mobile, Doppler radars scanned several tornadoes at close range in south-central Kansas on 12 May 2004. The detailed vertical structure of the Doppler wind and radar reflectivity fields of one of the tornadoes is described with the aid of boresighted video. The inside wall of a weak-echo hole inside the tornado was terminated at the bottom as a bowl-shaped boundary within several tens of meters of the ground. Doppler signatures of horizontal vortices were noted along one edge in the lowest 500 m of the tornado. The vertical structure of Doppler velocity displayed significant variations on the 100-m scale. Near the center of the tornado, a quasi-horizontal, radial bulge of the weak-echo hole at ∼500–600 m AGL dropped to about 400 m above the ground and was evident as a weak-echo band to the south of the tornado. It is suggested that this feature represents echo-weak material transported radially outward by a vertical circulation. Significant vertical variations of Doppler velocity were found in the surface friction layer both inside and outside the tornado core. The shape of a weak-echo notch that was associated with a hook echo wrapped around the tornado is described. Highest Doppler velocities were located outside the condensation funnel. The structure of the other tornadoes is also described, but with much less detail. Some of the analyses are compared with numerical simulations of tornado-like vortices done elsewhere.
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Liu, Guang Kui, Qun Yi Zhu und Xing Ying Zhu. „Effect of over-Fire Air Velocity on the Aerodynamic Characteristics in a Cold Model of an Arch-Fired Boiler with New over-Fire Air Arrangement“. Advanced Materials Research 610-613 (Dezember 2012): 1416–21. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.1416.
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A new over-fire air (OFA) program is proposed for Foster Wheeler (FW) type arch-fired boiler: the OFA nozzles are setting on arches near the furnace center and emitting OFA flow into the furnace at an inclined angle. Cold airflow experiments were conducted to determine the effect of the OFA velocity on the aerodynamic field in a small-scale furnace modeled for a 660-MWe arch-fired boiler. As the OFA velocity increases, the penetration depth of the OFA flow increases and the turning point of the OFA flow moves to the furnace center. At the same time, the vertical velocity of arch-injected airflow reduced faster because of the attracted effect of the OFA flow with higher velocity. When the OFA velocity is 22.39m/s (corresponding to 30m/s in the actual boiler), the OFA flow could penetrate to the furnace center and mix with the upflowing gas completely, while the arch-injected airflow have sufficient travel distance and enough residence time in the lower furnace. Thus, considering the penetration depth of arch-injected flow and the OFA flow, an OFA velocity of 22.39m/s recommended according to the present work.
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Riza, Muhammad, Erry Yulian Triblas Adesta und M. Yuhan Suprianto. „Cutting Temperature Behaviours in End Milling of Pocket by Applying Contour-In Tool Path Strategy“. Advanced Materials Research 1115 (Juli 2015): 47–50. http://dx.doi.org/10.4028/www.scientific.net/amr.1115.47.
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Cutting temperature generated during high speed machining operations has been recognized as major factors influence tool performance and workpiece geometry. This paper aims to model the cutting temperature and to investigate cutting temperature behaviours when contour-in tool path strategy applied in high speed end milling process. The experiments were carried out on CNC vertical machining center by involving PVD coated carbide inserts. Cutting speed, feed rate and depth of cut were set to vary. Results obtained indicate that cutting temperature is high in the initial stage of milling and at the corners region or turning points region. Portion of radial width of cut with workpiece in combination with the abrupt change of the milling path direction occur particularly in acute internal corners of a pocket leads to rise of cutting temperature.
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Baidar, Sunil, Natalie Kille, Ivan Ortega, Roman Sinreich, David Thomson, James Hannigan und Rainer Volkamer. „Development of a digital mobile solar tracker“. Atmospheric Measurement Techniques 9, Nr. 3 (08.03.2016): 963–72. http://dx.doi.org/10.5194/amt-9-963-2016.
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Abstract. We have constructed and deployed a fast digital solar tracker aboard a moving ground-based platform. The tracker consists of two rotating mirrors, a lens, an imaging camera, and a motion compensation system that provides the Euler angles of the mobile platform in real time. The tracker can be simultaneously coupled to UV–Vis and Fourier transform infrared spectrometers, making it a versatile tool to measure the absorption of trace gases using solar incoming radiation. The integrated system allows the tracker to operate autonomously while the mobile laboratory is in motion. Mobile direct sun differential optical absorption spectroscopy (mobile DS-DOAS) observations using this tracker were conducted during summer 2014 as part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) in Colorado, USA. We demonstrate an angular precision of 0.052° (about 1/10 of the solar disk diameter) during research drives and verify this tracking precision from measurements of the center to limb darkening (CLD, the changing appearance of Fraunhofer lines) in the mobile DS-DOAS spectra. The high photon flux from direct sun observation enables measurements of nitrogen dioxide (NO2) slant columns with high temporal resolution and reveals spatial detail in the variations of NO2 vertical column densities (VCDs). The NO2 VCD from DS-DOAS is compared with a co-located MAX-DOAS instrument. Overall good agreement is observed amid a highly heterogeneous air mass.
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Baidar, S., N. Kille, I. Ortega, R. Sinreich, D. Thomson, J. Hannigan und R. Volkamer. „Development of a digital mobile solar tracker“. Atmospheric Measurement Techniques Discussions 8, Nr. 11 (02.11.2015): 11401–27. http://dx.doi.org/10.5194/amtd-8-11401-2015.
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Abstract. We have constructed and deployed a fast digital solar tracker aboard a moving ground-based platform. The tracker consists of two rotating mirrors, a lens, an imaging camera, and a motion compensation system that provides the Euler angles of the mobile platform in real time. The tracker can be simultaneously coupled to UV-Vis and FTIR spectrometers making it a versatile tool to measure the absorption of trace gases using solar incoming radiation. The integrated system allows the tracker to operate autonomously while the mobile laboratory is in motion. Mobile direct sun Differential Optical Absorption Spectroscopy (mobile DS-DOAS) observations using this tracker were conducted during summer 2014 as part of the Front Range Photochemistry and Pollution Experiment (FRAPPE) in Colorado, USA. We demonstrate an angular precision of 0.052° (about 1/10 of the solar disk diameter) during research drives, and verify this tracking precision from measurements of the center to limb darkening (CLD, the changing appearance of Fraunhofer lines) in the mobile DS-DOAS spectra. The high photon flux from direct sun observation enables measurements of nitrogen dioxide (NO2) slant columns with high temporal resolution, and reveals spatial detail in the variations of NO2 vertical column densities (VCDs). The NO2 VCD from DS-DOAS is compared with a co-located MAX-DOAS instrument. Overall good agreement is observed amid a highly heterogeneous air mass.
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Karmiadji, Djoko Wahyu, Muchamad Gozali, Muji Setiyo, Thirunavukkarasu Raja und Tuessi Ari Purnomo. „Comprehensive Analysis of Minibuses Gravity Center: A Post-Production Review for Car Body Industry“. Mechanical Engineering for Society and Industry 1, Nr. 1 (19.07.2021): 31–40. http://dx.doi.org/10.31603/mesi.5250.
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The center of gravity (CoG) on the minibus is one of the fundamental parameters that affect the operation of the vehicle to maintain traffic safety. CoG greatly affects vehicle maneuverability due to load transfer between the front and rear wheels, such as when turning, braking, and accelerating. Therefore, this research was conducted to evaluate the operational safety of minibusses produced by the domestic car body industry. The case study was conducted on a minibus with a capacity of 30 passengers to be used in a mining area. Investigations on CoG were carried out based on the minibus specification data, especially the dimensions and forces acting on the wheels. Minibusses as test objects were categorized in two conditions, namely without passengers and with 30 passengers. The test results are expressed in a coordinate system (x, y, z) which represents the longitudinal, lateral, and vertical distances to the center of the front wheel axle. CoG coordinate values without passengers are (2194.92; 7.11; 1327.97) mm and CoG coordinates with full passengers (30 people) are (2388.52; 13.04; 1251.72) mm. The test results show that the change in CoG at full load is not significant which indicates the minibus is safe when maneuvering under normal conditions.
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Teso-Fz-Betoño, Daniel, Ekaitz Zulueta, Ander Sánchez-Chica, Unai Fernandez-Gamiz und Aitor Saenz-Aguirre. „Semantic Segmentation to Develop an Indoor Navigation System for an Autonomous Mobile Robot“. Mathematics 8, Nr. 5 (25.05.2020): 855. http://dx.doi.org/10.3390/math8050855.
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In this study, a semantic segmentation network is presented to develop an indoor navigation system for a mobile robot. Semantic segmentation can be applied by adopting different techniques, such as a convolutional neural network (CNN). However, in the present work, a residual neural network is implemented by engaging in ResNet-18 transfer learning to distinguish between the floor, which is the navigation free space, and the walls, which are the obstacles. After the learning process, the semantic segmentation floor mask is used to implement indoor navigation and motion calculations for the autonomous mobile robot. This motion calculations are based on how much the estimated path differs from the center vertical line. The highest point is used to move the motors toward that direction. In this way, the robot can move in a real scenario by avoiding different obstacles. Finally, the results are collected by analyzing the motor duty cycle and the neural network execution time to review the robot’s performance. Moreover, a different net comparison is made to determine other architectures’ reaction times and accuracy values.
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Yan, Hong Wei, und Yu Zhao. „Based on a Crawler Type Walking Mechanism Analysis and Research“. Advanced Materials Research 341-342 (September 2011): 442–46. http://dx.doi.org/10.4028/www.scientific.net/amr.341-342.442.
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Caterpillar walk agency is the supporting a large walk machinery, used to support the weight of the whole machine, inherit institution in engineering work force produces in the process, and complete the machine in March, backward, also, the mobile. Homework Therefore, to average large engineering machinery chassis general design into tracked drive structure, and tracked down the vertical center symmetrical layout. This paper mainly studied and discussed crawler walks the organization design principles and exercise stress analysis, summarized the influence factors of walking organization for the future, the design of the machine can achieve reasonable structure, safe and reliable, action flexible have laid a good foundation.
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Wada, Masayoshi. „Omnidirectional and Holonomic Mobile Platform with Four-Wheel-Drive Mechanism for Wheelchairs“. Journal of Robotics and Mechatronics 19, Nr. 3 (20.06.2007): 264–71. http://dx.doi.org/10.20965/jrm.2007.p0264.
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This paper presents a new type of omnidirectional and holonomic mobile platform with a four-wheel-drive (4WD) mechanism for improving traction of electric wheelchairs on slippery surfaces and enhancing mobility on rough terrain. The 4WD mechanism includes a pair of normal wheels on the back and a pair of omniwheels on the front. The normal wheel in back and the omniwheel in front, on the same side of the drive mechanism, are connected by a power transmission to rotate in unison with a common motor. Omniwheels enable the front of the mechanism to roll freely from side to side. A third motor turns the chair about a vertical axis at the center of the mobile platform. One goal of this project is to apply the 4WD mechanism to a holonomic omnidirectional mobile base for wheelchairs to enhance both maneuverability and mobility in single wheelchair design. The 4WD mechanism guarantees traction on irregular surfaces and enhances step climbing over that of standard wheelchairs because all wheels have a large diameter and no passive casters are used. For omnidirectional control of the 4WD mobile base, two wheel motors are coordinated to move the center of the chair in an arbitrary direction while chair orientation is controlled separately by the third motor. The three motors thus provide nonredundant 3DOF chair movement. A wheelchair with our proposed mobile base moves in all directions without changing chair orientation and turns in place, i.e., holonomic. The configuration minimizing number of motors cuts costs and ensures a high reliable mechanism. We analyze the kinematics of planar motion and statics on the wheel step of the synchronized 4WD, then discuss the development of omnidirectional 4WD control. A series of experiments using a small robotic vehicle verifies kinematic and static models and the feasibility of the 4WD omnidirectional system proposed.
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Hubbert, J. C., S. M. Ellis, W. Y. Chang und Y. C. Liou. „X-Band Polarimetric Observations of Cross Coupling in the Ice Phase of Convective Storms in Taiwan“. Journal of Applied Meteorology and Climatology 53, Nr. 6 (Juni 2014): 1678–95. http://dx.doi.org/10.1175/jamc-d-13-0360.1.
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AbstractIn this paper, experimental X-band polarimetric radar data from simultaneous transmission of horizontal (H) and vertical (V) polarizations (SHV) are shown, modeled, and microphysically interpreted. Both range–height indicator data and vertical-pointing X-band data from the Taiwan Experimental Atmospheric Mobile-Radar (TEAM-R) are presented. Some of the given X-band data are biased, which is very likely caused by cross coupling of the H and V transmitted waves as a result of aligned, canted ice crystals. Modeled SHV data are used to explain the observed polarimetric signatures. Coincident data from the National Center for Atmospheric Research S-band polarimetric radar (S-Pol) are presented to augment and support the X-band polarimetric observations and interpretations. The polarimetric S-Pol data are obtained via fast-alternating transmission of horizontal and vertical polarizations (FHV), and thus the S-band data are not contaminated by the cross coupling (except the linear depolarization ratio LDR) observed in the X-band data. The radar data reveal that there are regions in the ice phase where electric fields are apparently aligning ice crystals near vertically and thus causing negative specific differential phase Kdp. The vertical-pointing data also indicate the presence of preferentially aligned ice crystals that cause differential reflectivity Zdr and differential phase ϕdp to be strong functions of azimuth angle.
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Archer, Cristina L., und Mark Z. Jacobson. „The Santa Cruz Eddy. Part II: Mechanisms of Formation“. Monthly Weather Review 133, Nr. 8 (01.08.2005): 2387–405. http://dx.doi.org/10.1175/mwr2979.1.
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Abstract The formation mechanism of the Santa Cruz eddy (SCE) is investigated using the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5). Simulations of 25–26 August 2000 showed that two eddy instances formed on that night, a finding supported by observations. The two eddies had similar behavior: they both formed in the sheltered Santa Cruz, California, area and then moved southeastward, to finally dissipate after 7–11 h. However, the first eddy had greater vorticity, wind speed, horizontal and vertical extents, and lifetime than the second eddy. Numerical simulations showed that the SCEs are formed by the interaction of the main northwesterly flow with the topographic barrier represented by the Santa Cruz Mountains to the north of Monterey Bay. Additional numerical experiments were undertaken with no diurnal heating cycle, no (molecular or eddy) viscosity, and no horizontal thermal gradients at ground level. In all cases, vertical vorticity was still created by the tilting of horizontal vorticity generated by the solenoidal term in the vorticity equation. This baroclinic process appeared to be the fundamental formation mechanism for both SCEs, but more favorable conditions in the late afternoon (including a south-to-north pressure gradient, flow turning due to the sea breeze, and an expansion fan) coincided to intensify the first eddy.
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Wakimoto, Roger M., Nolan T. Atkins, Kelly M. Butler, Howard B. Bluestein, Kyle Thiem, Jeffrey Snyder und Jana Houser. „Photogrammetric Analysis of the 2013 El Reno Tornado Combined with Mobile X-Band Polarimetric Radar Data“. Monthly Weather Review 143, Nr. 7 (01.07.2015): 2657–83. http://dx.doi.org/10.1175/mwr-d-15-0034.1.
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Abstract This study presents rapid-scanning X-band polarimetric radar data combined with photogrammetry of the El Reno tornado of 31 May 2013. The relationship between the hook echo, weak-echo hole (WEH), weak-echo column (WEC), and the rotational couplet with the visual characteristics of the tornado are shown. For the first time, cross-correlation coefficient (ρhv) and differential reflectivity (ZDR) data are included in the photogrammetric analyses. The tornado was accompanied by a large tornadic debris signature (TDS) with a diameter ~2 km wide during the analysis time. The center of the TDS was not collocated with the WEH and the rotational couplet. Instead, the TDS was displaced ~1 km to the north and within the weak-echo notch of the hook echo. A “debris overhang” was identified in vertical cross sections of the ρhv fields. The overhang was located in a weak-echo trench and a notch of high ρhv, consistent with the position of the tornado updraft. The updraft was hypothesized to be carrying small debris particles to heights that produced the overhang signature. A U-shaped band of high ρhv and ZDR was resolved in a vertical cross section and positioned at the periphery of the WEC during one of the analysis times. It was proposed that the band formed as a result of hydrometeors encircling the WEC while being surrounded on all sides by relatively hydrometeor-free air. The characteristics of the scatterers within the WEC were resolved and believed to be composed of a low concentration of very small, randomly oriented, debris particles, even in the presence of strong centrifuging, and a general absence of hydrometeors.
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Ottaviani, Marco, Luca Giammichele und Renato Ricci. „Design, Assembly and Testing of a Mobile Laboratory Based on a VTOL Scale Motorglider“. Tecnica Italiana-Italian Journal of Engineering Science 65, Nr. 2-4 (30.07.2021): 414–21. http://dx.doi.org/10.18280/ti-ijes.652-440.
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The objective of this paper is to explain the design steps and performance analysis of a vertical take-off and landing (VTOL) unmanned air vehicle (UAV) based on a Pilatus B4 glider scale model. Energy consumption, forces and thrust analyses are carry out to determinate the perfect match between low take-off weight and high aerodynamic performance. As a first approach a complete analysis of glider aerodynamic performances are settle to understand and design a proper support for VTOL conversion. Longitudinal static stability is fulfilled by evaluating the center of gravity location with respect to neutral position, nevertheless dynamic stability, and V-n diagram in VTOL configuration are evaluated to guarantee a correct behavior during fixed wing flight mode. In addition, power requirements, motor thrust capability and tilt-motors servo assisted system performance are determinate in perspective of flight performance to find out the perfect transition from multirotor take-off and landing mode to fixed-wing flying state. For these purposes a test bench has being designed to evaluate thrust, electrical absorption and rpm motor behavior along the throttle range. Finally, the assembly and preliminary tests are performed in order to validate the VTOL and Forward flight capability.
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López-Moranchel, Ignacio, Luis M. Alegre, Patricia Maurelos-Castell, Vicent Picó Pérez und Ignacio Ara. „Theoretical Aspects for Calculating the Mobilized Load during Suspension Training through a Mobile Application“. Applied Sciences 11, Nr. 1 (29.12.2020): 242. http://dx.doi.org/10.3390/app11010242.
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Introduction: This study describes the theoretical foundations of the development of an equation that allows for the estimation of the mobilized load when training with suspension devices (type TRX®) and presents a mobile application as a means for its use. Methods: Systems of equations are proposed of which the terms depend on the angulation of the device with respect to the vertical (angle α), the relationship between the height of grip, the height of the center of mass and the weight of the subject, which are recorded from a photo. Results: Based on the photo and the subject’s standing height, the application allows the user to measure the angle α, providing the values of applied force (in N) and mobilized load in relation to the percentage of body mass, applying the calculations described in our equations. The equation also provides the estimated value of the load mobilized during a push up on the floor (68% of the subject’s body mass) and the equation for the calculation of the mobilized load when the suspension device is fixed to the feet. Conclusions: It is possible to use equations to estimate the load mobilized in each repetition during training using suspension devices and to implement this algorithm in a mobile application.
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Schwaner, M. Janneke, Grace A. Freymiller, Rulon W. Clark und Craig P. McGowan. „How to Stick the Landing: Kangaroo Rats Use Their Tails to Reorient during Evasive Jumps Away from Predators“. Integrative and Comparative Biology 61, Nr. 2 (03.05.2021): 442–54. http://dx.doi.org/10.1093/icb/icab043.
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Synopsis Tails are widespread in the animal world and play important roles in locomotor tasks, such as propulsion, maneuvering, stability, and manipulation of objects. Kangaroo rats, bipedal hopping rodents, use their tail for balancing during hopping, but the role of their tail during the vertical evasive escape jumps they perform when attacked by predators is yet to be determined. Because we observed kangaroo rats swinging their tails around their bodies while airborne following escape jumps, we hypothesized that kangaroo rats use their tails to not only stabilize their bodies while airborne, but also to perform aerial re-orientations. We collected video data from free-ranging desert kangaroo rats (Dipodomys deserti) performing escape jumps in response to a simulated predator attack and analyzed the rotation of their bodies and tails in the yaw plane (about the vertical-axis). Kangaroo rat escape responses were highly variable. The magnitude of body re-orientation in yaw was independent of jump height, jump distance, and aerial time. Kangaroo rats exhibited a stepwise re-orientation while airborne, in which slower turning periods corresponded with the tail center of mass being aligned close to the vertical rotation axis of the body. To examine the effect of tail motion on body re-orientation during a jump, we compared average rate of change in angular momentum. Rate of change in tail angular momentum was nearly proportional to that of the body, indicating that the tail reorients the body in the yaw plane during aerial escape leaps by kangaroo rats. Although kangaroo rats make dynamic 3D movements during their escape leaps, our data suggest that kangaroo rats use their tails to control orientation in the yaw plane. Additionally, we show that kangaroo rats rarely use their tail length at full potential in yaw, suggesting the importance of tail movement through multiple planes simultaneously.
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Mu, Da, Quan Yong Li, Bo Qi Wu und Yu Nan Du. „Research on the Online Test Principle and Error Analysis of Aspherical Optical Surfaces“. Key Engineering Materials 552 (Mai 2013): 434–39. http://dx.doi.org/10.4028/www.scientific.net/kem.552.434.
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For tFor t For tFor the imaging advantages of aspheric optical component, it has been widely used in the aviation, aerospace, defense and civilian high-technology. Aspherical surface shape test is a key factor restricted aspheric processing and a complex sophisticated testing techniques. The well known measurement methods are faulty. Each method has advantages and disadvantages; many methods cannot be used for online testing. In this paper，the geometric principle of a swing-arm profilometer as a novel method to measure aspherics is introduced．The deviation between the actual and the ideal of aspherical surface shape is confirmed by the high-precision measurement for the vertical height with a specific path on the aspherical optical surfaces. By adjusting the location of measuring devices to maintain the distance of rotation center to the center of workpiece equal to the length of swing-arm,we can achieve the measurement for the workpiece of different machining tool. The measurement system mainly consists of the lifting and landing system of the high-precision axis,the high-precision level turntable rotary table, the high rigidity measuring arm and the high precision measurement sensors. And the follow-up data processing puts forward a number of error correction models at the same time. The advantages of the measurement method are that the measurement sports is only a simple turning motion .It will be helpful to reduce measurement errors and improve the efficiency of measurement.
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Silva, Paula Alexandra, Roxanne Leitão und Maureen K. Kerwin. „Tap and Swipe Activity Zones on Smartphones for Novice Older Adults“. International Journal of Creative Interfaces and Computer Graphics 9, Nr. 2 (Juli 2018): 18–39. http://dx.doi.org/10.4018/ijcicg.2018070102.
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This article investigates tactile interaction on smartphones with adults aged 65 or older who were considered to have a novice level of skill with technology. Two experiments with two different groups of 40 Portuguese adults adds empirical evidence to the field and shows that older adult performance for tapping is best toward the center, right edge, and bottom right corner of the smartphone display. Results also show that a participant's performance of horizontal swipes is better with targets toward the bottom half of the display, while participant's performance of vertical swipes is better with targets toward the right half of the display. This article contributes to the body of research on the design of user interfaces for smartphones and mobile applications targeted at older adults, as well as providing practical information for designers and practitioners developing products that are more universally accessible.
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Cronce, Marcia, Robert M. Rauber, Kevin R. Knupp, Brian F. Jewett, Justin T. Walters und Dustin Phillips. „Vertical Motions in Precipitation Bands in Three Winter Cyclones“. Journal of Applied Meteorology and Climatology 46, Nr. 10 (01.10.2007): 1523–43. http://dx.doi.org/10.1175/jam2533.1.
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Abstract The University of Alabama in Huntsville Mobile Integrated Profiling System 915-MHz profiler was deployed in January and February of 2004 to measure vertical air velocities in finescale precipitation bands in winter cyclones. The profiler was placed to sample the “wraparound” quadrant of three winter cyclones in the central and southern United States, and it obtained high-resolution measurements of the vertical structure of a series of bands in each storm. The data revealed bands that were up to 6 km deep, 10–50 km wide, and spaced about 5–20 km apart. Measurements of vertical air motion w within these bands were retrieved from the Doppler spectra using the lower-bound method, adapted to account for the effects of spectral broadening caused by the horizontal wind, wind shear, and turbulence. Derived vertical air motions ranged from −4.3 to 6.7 m s−1, with an uncertainty of about ±0.6 m s−1. Approximately 29% of the 1515 total derived values were negative, 35% exceeded 1 m s−1, and 9% exceeded 2.0 m s−1. These values are consistent with studies in the Pacific Northwest, except that more extreme values were observed in one band than have been previously reported. There was a high correlation between values of signal-to-noise ratio (SNR) and w within each band (0.60 ≤ r ≤ 0.85), in the composite of bands from each cyclone (0.59 ≤ r ≤ 0.79), and in the overall analysis (r = 0.68). The strongest updrafts were typically between 2.0 and 4.0 m s−1 and were located near the center of each band in regions of high SNR. Regions of downdrafts within the bands had maximum values between −1.0 and −4.3 m s−1 and were typically located along the edges of the bands in regions of low SNR. These results are consistent with snow growth and sublimation processes. The magnitudes of the vertical velocities in the core of the bands were comparable to theoretical predictions for moist symmetric instability (MSI) under inviscid conditions but would appear to be somewhat larger than expected for MSI when turbulent mixing is considered, suggesting that other instabilities, such as potential instability, may have contributed to the band development in these storms.
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Palm, S., R. Sommer, A. Tessmann und U. Stilla. „ULTRA-HIGH RESOLUTION IMAGING OF FACADES AND VERTICAL INFRASTRUCTURE BY CARBORNE SAR AND AIRBORNE CSAR“. ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2/W7 (16.09.2019): 129–36. http://dx.doi.org/10.5194/isprs-annals-iv-2-w7-129-2019.
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<p><strong>Abstract.</strong> In this paper we propose a strategy to focus ultra-high resolution single channel carborne SAR and airborne circular SAR (CSAR) data to image facades and vertical infrastructure. We illustrate the related theoretical background and the design of an optimal focusing geometry for carborne SAR applications while using backprojection focusing techniques. Of particular interest is thereby the determination of the minimum distance and orientation of the facade to the radar sensor. Potential image distortions due to a wrong choice of these parameters are illustrated. Effects on the final resolution of the data due to the rotation of the focusing geometry compared to typical airborne SAR are discussed. We validated the strategy by driving on conventional roads illuminating facades with an experimental mobile radar mapping (MRM) sensor operating at 300 GHz. We further present an adapted version of the proposed strategy to focus vertical infrastructure in CSAR data sets. By extracting the center coordinate and the principal orientation of an object from GiS data, the focusing plane is designed arbitrarily in the 3D space. For the CSAR data set, a radar sensor particularly designed for circular flight trajectories operating at 94 GHz was evaluated. An electrical pylon was chosen as potential target. In both applications, the final images show a high level of detail. The combination of proposed strategy and radar sensor with very high bandwidth is capable of subcentimeter imaging of facades. The height, shape and dimensions of objects can be extracted directly from the image geometry at very high accuracy.</p>
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Lee, Wen-Chau, und Joshua Wurman. „Diagnosed Three-Dimensional Axisymmetric Structure of the Mulhall Tornado on 3 May 1999“. Journal of the Atmospheric Sciences 62, Nr. 7 (01.07.2005): 2373–93. http://dx.doi.org/10.1175/jas3489.1.
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Abstract On 3 May 1999, an unusually large tornado that caused F4-level damage and killed several people was intercepted by the Doppler on Wheels (DOW) mobile radar near Mulhall, Oklahoma, from a range of 4 to 9 km, resulting in high-resolution volumetric data every 55 s up to 1.5-km altitude over a period of 14 min. For the first time, the evolution and three-dimensional structure of a tornado were deduced using the ground-based velocity track display (GBVTD) technique. After the circulation center was determined, the tangential wind and radial wind were derived from the GBVTD technique at each radius and height. In addition, the axisymmetric vertical velocity, angular momentum, vorticity, and perturbation pressure were deduced from the tangential and radial wind fields. This study focuses on the axisymmetric aspects of this tornado. The primary circulation of the Mulhall tornado consisted of an 84 m s−1 peak axisymmetric tangential wind with the radius of maximum wind (RMW) ranging from 500 to 1000 m. The secondary circulation exhibited a two-cell structure characterized by a central downdraft surrounded by an annular updraft near the RMW. The calculated maximum pressure deficit from a 3-km radius to the tornado center at 50-m altitude was −80 hPa. The maximum vorticity during the first 8 min of observation was located inside the RMW away from the tornado center. This vorticity profile satisfied the necessary condition of barotropic instability. As the tornado weakened afterward, the vorticity monotonically increased toward the center. The computed swirl ratios were between 2 and 6, consistent with the observed multiple vortex radar signatures and the vorticity pattern. Swirl ratios were generally smaller during the weakening phase.
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Han, Yulong, Haili Sun und Ruofei Zhong. „Three-Dimensional Linear Restoration of a Tunnel Based on Measured Track and Uncontrolled Mobile Laser Scanning“. Sensors 21, Nr. 11 (31.05.2021): 3815. http://dx.doi.org/10.3390/s21113815.
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Traditional precision measurement adopts discrete artificial static observation, which cannot meet the demands of the dynamic, continuous, fine and high-precision holographic measurement of large-scale infrastructure construction and complex operation and maintenance management. Due to its advantages of fast, accurate and convenient measurement, mobile laser scanning technology is becoming a popular technology in the maintenance and measurement of infrastructure construction such as tunnels. However, in some environments without satellite signals, such as indoor areas and underground spaces, it is difficult to obtain 3D data by means of mobile measurement technology. This paper proposes a method to restore the linear of the point cloud obtained by mobile laser scanning based on the measured track center line. In this paper, the measured track position is interpolated with a cubic spline to calculate the translations, and the rotation parameters are calculated by combining the simulation design data. The point cloud of the cross-section of the tunnel under the local coordinate system is converted to the absolute coordinate system to calculate the tunnel line. In addition, the method is verified by experiments combined with the subway tunnel data, and the overall point error can be controlled to within 0.1 m. The average deviation in the horizontal direction is 0.0551 m, and that in the vertical direction is 0.0274 m. Compared with the previous methods, this method can effectively avoid the obvious deformation of the tunnel and the sharp increase in the error, and can process the tunnel point cloud data more accurately and quickly. It also provides better data support for subsequent tunnel analysis such as 3D display, completion survey, systematic hazard management and so on.
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Weisman, Morris L., Robert J. Trapp, Glen S. Romine, Chris Davis, Ryan Torn, Michael Baldwin, Lance Bosart et al. „The Mesoscale Predictability Experiment (MPEX)“. Bulletin of the American Meteorological Society 96, Nr. 12 (01.12.2015): 2127–49. http://dx.doi.org/10.1175/bams-d-13-00281.1.
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Abstract The Mesoscale Predictability Experiment (MPEX) was conducted from 15 May to 15 June 2013 in the central United States. MPEX was motivated by the basic question of whether experimental, subsynoptic observations can extend convective-scale predictability and otherwise enhance skill in short-term regional numerical weather prediction. Observational tools for MPEX included the National Science Foundation (NSF)–National Center for Atmospheric Research (NCAR) Gulfstream V aircraft (GV), which featured the Airborne Vertical Atmospheric Profiling System mini-dropsonde system and a microwave temperature-profiling (MTP) system as well as several ground-based mobile upsonde systems. Basic operations involved two missions per day: an early morning mission with the GV, well upstream of anticipated convective storms, and an afternoon and early evening mission with the mobile sounding units to sample the initiation and upscale feedbacks of the convection. A total of 18 intensive observing periods (IOPs) were completed during the field phase, representing a wide spectrum of synoptic regimes and convective events, including several major severe weather and/or tornado outbreak days. The novel observational strategy employed during MPEX is documented herein, as is the unique role of the ensemble modeling efforts—which included an ensemble sensitivity analysis—to both guide the observational strategies and help address the potential impacts of such enhanced observations on short-term convective forecasting. Preliminary results of retrospective data assimilation experiments are discussed, as are data analyses showing upscale convective feedbacks.
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Deliagina, T. G., G. N. Orlovsky, A. I. Selverston und Y. I. Arshavsky. „Neuronal Mechanisms for the Control of Body Orientation inClione I. Spatial Zones of Activity of Different Neuron Groups“. Journal of Neurophysiology 82, Nr. 2 (01.08.1999): 687–99. http://dx.doi.org/10.1152/jn.1999.82.2.687.
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The marine mollusk Clione limacina,when swimming, can stabilize different body orientations in the gravitational field. Here we describe one of the modes of operation of the postural network in Clione—maintenance of the vertical, head-up orientation. Experiments were performed on the CNS-statocyst preparation. Spike discharges in the axons of different types of neurons were recorded extracellularly when the preparation was rotated in space through 360° in different planes. We characterized the spatial zones of activity of the tail and wing motor neurons as well as of the CPB3 interneurons mediating the effects of statocyst receptor cells on the tail motor neurons. It was found that the activity of the tail motor neurons increased with deviation of the preparation from the normal, rostral-side-up orientation. Their zones of activity were very wide (∼180°). According to the zone position, three distinct groups of tail motor neuron (T1–T3) could be distinguished. The T1 group had a center of the zone near the ventral-side-up orientation, whereas the zones of T2 and T3 had their centers near the left-side-up and the right-side-up positions, respectively. By comparing the zone of activity with the direction of tail bending elicited by each of the groups, one can conclude that gravitational reflexes mediated by the T1, T2, and T3 groups will evoke turning of the animal toward the head-up orientation. Two identified wing motor neurons, 1A and 2A, causing the wing beating, were involved in gravitational reactions. They were activated with the downward inclination of the ipsilateral side. Opposite reactions were observed in the motor neurons responsible for the wing retraction. A presumed motor effect of these reactions is an increase of oscillations in the wing that is directed downward and turning of Clionetoward the head-up orientation. Among the CPB3 interneurons, at least four groups could be distinguished. In three of them (IN1, IN2, and IN3), the zones of activity were similar to those of the three groups (T1, T2, and T3) of the tail motor neurons. The group IN4 had the center of its zone in the dorsal-side-up position; a corresponding group was not found among the tail motor neurons. In lesion experiments, it was found that gravitational input mediated by a single CPB3 interneuron produced activation of its target tail motor neurons in their normal zones, but the strength of response was reduced considerably. This finding suggests that several interneurons with similar spatial zones converge on individual tail motor neurons. In conclusion, because of a novel method, activity of the neuronal network responsible for the postural control in Clione was characterized in the terms of gravitational responses in different neuron groups comprising the network.
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Wang, X. Y., und K. C. Wang. „Estimation of atmospheric mixing layer height from radiosonde data“. Atmospheric Measurement Techniques 7, Nr. 6 (12.06.2014): 1701–9. http://dx.doi.org/10.5194/amt-7-1701-2014.
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Abstract. Mixing layer height (h) is an important parameter for understanding the transport process in the troposphere, air pollution, weather and climate change. Many methods have been proposed to determine h by identifying the turning point of the radiosonde profile. However, substantial differences have been observed in the existing methods (e.g. the potential temperature (θ), relative humidity (RH), specific humidity (q) and atmospheric refractivity (N) methods). These differences are associated with the inconsistency of the temperature and humidity profiles in a boundary layer that is not well mixed, the changing measurability of the specific humidity and refractivity with height, the measurement error of humidity instruments within clouds, and the general existence of clouds. This study proposes a method to integrate the information of temperature, humidity and cloud to generate a consistent estimate of h. We apply this method to high vertical resolution (~ 30 m) radiosonde data that were collected at 79 stations over North America during the period from 1998 to 2008. The data are obtained from the Stratospheric Processes and their Role in Climate Data Center (SPARC). The results show good agreement with those from N method as the information of temperature and humidity contained in N; however, cloud effects that are included in our method increased the reliability of our estimated h. From 1988 to 2008, the climatological h over North America was 1675 ± 303 m with a strong east–west gradient: higher values (generally greater than 1800 m) occurred over the Midwest US, and lower values (usually less than 1400 m) occurred over Alaska and the US West Coast.
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Wada, Masayoshi. „A 4WD Omnidirectional Wheelchair with Enhanced Step Climbing Capability“. Journal of Robotics and Mechatronics 20, Nr. 6 (20.12.2008): 846–53. http://dx.doi.org/10.20965/jrm.2008.p0846.
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In developing an omnidirectional wheelchair tilted to climb single high steps, we enhanced standard step climbing by introducing a four-wheel drive (4WD). One pair of front and back wheels is connected by transmission belts to rotate in unison with a drive motor, i.e., synchrodrive transmission. To avoid wheel slippage as the mechanism turns, two omniwheels are installed in front and two regular tires in back, enabling the front wheels to slide freely sideways while the two back wheels continuously contact the ground. A third motor on the 4WD platform rotates the chair at the center of the mobile base around the vertical axis. The 4WD enhances step climbing over that of standard wheelchairs, but back wheels limit the step height climbed, meaning that front wheels climb higher steps than back wheels. We analyzed 4WD statics to clarify differences in front and back wheel step climbing, finding that drive torque caused the difference and that this influence depends on the wheelbase and vehicle weight distribution ratio of the front and back wheel axes. We varied the load distribution ratio among wheels to maximize back wheel step climbing. To do so, we developed chair tilting with a linear drive and an inclination sensor. The linear drive changes the chair's tilt angle for keeping the wheelchair statics and to vary positioning of the center of gravity (COG) to enable back wheels to climb steps more efficiently. To confirm the effectiveness of chair tilting in this scheme, we tested step climbing in experiments in which a prototype wheelchair carrying a user climbed a 90 mm step, but the back wheels failed when chair tilting was disabled.
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Amid, Reza, Mahdi kadkhodazadeh, Farshad Dehnavi und Mahyar Brokhim. „Comparison of Stress and Strain Distribution around Splinted and Non-splinted Teeth with Compromised Periodontium: A Three-dimensional Finite Element Analysis“. Journal of Advanced Periodontology & Implant Dentistry 10, Nr. 1 (10.10.2018): 35–41. http://dx.doi.org/10.15171/japid.2018.007.
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Background. Splinting of teeth is performed for effective distribution of loads in mobile teeth and to lower the stress applied to compromised teeth. Biomechanics cannot adequately explain load distribution around natural teeth. This study aimed to compare the distribution pattern and magnitude of stress and strain around splinted and non-splinted teeth with compromised periodontium using three-dimensional (3D) finite element analysis (FEA). Methods. Six mandibular anterior teeth were scanned and data were registered in CATIA® and then SolidWorks® software programs. The jawbone was also designed. In the second model, the teeth were splinted with fiber-reinforced composite (FRC). The models were then transferred to ANSYS® software program and after meshing and fixing, 100- and 200-N loads were applied at zero and 30° angles. The magnitude and distribution of stress and strain in the periodontal ligament (PDL) and the surrounding cortical bone were determined. Results. A significant reduction in stress was noted in cortical bone around central and lateral incisors while an increase in stress was noted around the canine tooth after splinting. All these changes were more significant under 100-N load compared to 200-N load and greater differences were noted in response to the application of oblique loads compared to vertical loads. Conclusion. Splinting decreased the magnitude of stress and strain in teeth close to the center of splint and increased the stress and strain in teeth far from the center of splint. Adequate bone support of canine teeth must be ensured prior to selection of splinting as the treatment plan for the anterior mandible since it increases the longevity of all the teeth.
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Wang, X. Y., und K. C. Wang. „Estimation of atmospheric mixing layer height from radiosonde data“. Atmospheric Measurement Techniques Discussions 7, Nr. 2 (10.02.2014): 1247–73. http://dx.doi.org/10.5194/amtd-7-1247-2014.
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Abstract. Mixing layer height (h) is an important parameter for understanding the transport process in the troposphere, air pollution, weather and climate change. Many methods have been proposed to determine h by identifying the turning point of the radiosonde profile. However, substantial differences have been observed in the existing methods (e.g., the potential temperature (θ), relative humidity (RH), specific humidity (q) and atmospheric refractivity (N) methods). These differences are associated with the inconsistency of the temperature and humidity profiles in a boundary layer that is not well mixed, the changing measurability of the specific humidity and refractivity with height, the measurement error of humidity instruments within clouds, and the general existence of clouds. This study proposes a method to integrate the information of temperature, humidity and cloud to generate a consistent estimate of h. We apply this method to high vertical resolution (~ 30 m) radiosonde data that were collected at 79 stations over North America during the period from 1998 to 2008; the data are obtained from the Stratospheric Processes and their Role in Climate Data Center (SPARC). The results show good agreement with those from N method as the information of temperature and humidity contained in N; however cloud effects that are included in our method increased the reliability of h. Furthermore, our results agree well with the independent h that was determined from lidar observations. From 1988 to 2008, the climatological h over North America was 1675± 303 m with a strong east–west gradient: higher values (generally greater than 1800 m) occurred over the Midwest US, and lower values (usually less than 1400 m) occurred over Alaska and the US west coast.
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Berdnikov, A. A., R. V. Strel'tsov, V. A. Dyunov und I. V. Zol'nikov. „Mobility of aggregates of promising missile systems based on road trains with an active trailed link“. Izvestia MGTU MAMI 1, Nr. 3 (2020): 23–28. http://dx.doi.org/10.31992/2074-0530-2020-45-3-23-28.
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The aggregates of advanced missile systems (AAMS) include autonomous launchers of a mobile ground missile complex, transport-and-installation, refueling, maintenance and auxiliary technical means of technological equipment, which must have operational, tactical and strategic mobility. Operationaland tactical mobility is understood as the ability of the AAMS to move from one point to another in a certain time. Strategic mobility is characterized by the adaptability of the AAMS to its loading and transporting by other types of transport, including rail, air, water. The average speed of movement is taken as a measure of mobility, which should be developed by AAMS in order to ensure the timeliness, efficiency and safety of performing the assigned tasks, as well as the possibil-ity of getting out of the influence of the damaging factors of a nuclear explosion, primarily from excess pressure in the front of the shock blast wave. It is possible to increase the mobility of the AAMS by locating it on the basis of road trains, however, the existing designs of aggregates of road trains have disadvantages that reduce the flotation and, as a result, the average speed of movement, these include low support and geometric flotation. The geometric flotation is influenced by design factors. For example, an increase in overall width is typical for a road train, as the trailing link under the influence of lateral reactions of the supporting surface relative to the tractor track is shifted towards the instantaneous turning center. This displacement causes an increase in resistance to movement on deformable soils, and, consequently, a deterioration in flotation and a decrease in a number of other operational properties of the road train. It is possible to increase the mobility of the AAMS by placing them on the basis of a road train with an active trailed link, controlling the distri-bution of power flows supplied to the wheels of an all-wheel drive road train depending on the pos-sibility of realizing free traction by each wheel, changing the position of the road train center of in-flexions depending on the steering wheel angle and maneuver.
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Saint-Amour, Paul K. „Applied Modernism“. Theory, Culture & Society 28, Nr. 7-8 (Dezember 2011): 241–69. http://dx.doi.org/10.1177/0263276411423938.
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This article is about a period of technology transfer – the late 1910s and 1920s – when wartime aerial reconnaissance techniques and operations were being adapted to a range of civilian uses, including urban planning, land use analysis, traffic control, tax equalization, and even archaeology. At the center of the discussion is the ‘photomosaic’: a patchwork of overlapping aerial photographs that have been rectified and fit together so as to form a continuous survey of a territory. Initially developed during the First World War to provide coverage of fronts, photomosaic mapping was widely practiced and celebrated during the postwar years as an aid to urban development. The article traces both the refinements in photomosaic technology after the Armistice and the rhetorical means by which the form’s avant-garde wartime reputation was domesticated into an ‘applied realism’ that often effaced its site-specific perspective, its elaborately rectified optics, and the oppositionality of both its military and civilian uses. The article has a broader theoretical aim as well. Classic statements of both structuralist and post-structuralist spatial theory (Barthes and de Certeau are the primary examples here) have produced an ossified geometry wherein the vertical is the axis of paradigm, top-down strategy, and manipulative distance and the horizontal the axis of syntagm, grassroots tactics, and resistant proximities and differences. In its close study of the technology and rhetoric surrounding interwar photogrammetry, the article provides an example of how one might reverse the long-standing misrecognition of high-altitude optics as effacing time, difference, and materiality – and what it might mean to view such optics as, instead, a resource in turning from abstract toward differential conceptions of both aerial photography and our theoretical habits. This turn I call ‘applied modernism’, a term that accesses both the wartime photomosaic’s affiliation with avant-garde painting and its insistence that portraits of the total are always projections from partial, specific vantages.
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Kille, Natalie, Sunil Baidar, Philip Handley, Ivan Ortega, Roman Sinreich, Owen R. Cooper, Frank Hase, James W. Hannigan, Gabriele Pfister und Rainer Volkamer. „The CU mobile Solar Occultation Flux instrument: structure functions and emission rates of NH<sub>3</sub>, NO<sub>2</sub> and C<sub>2</sub>H<sub>6</sub>“. Atmospheric Measurement Techniques 10, Nr. 1 (01.02.2017): 373–92. http://dx.doi.org/10.5194/amt-10-373-2017.
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Abstract. We describe the University of Colorado mobile Solar Occultation Flux instrument (CU mobile SOF). The instrument consists of a digital mobile solar tracker that is coupled to a Fourier transform spectrometer (FTS) of 0.5 cm−1 resolution and a UV–visible spectrometer (UV–vis) of 0.55 nm resolution. The instrument is used to simultaneously measure the absorption of ammonia (NH3), ethane (C2H6) and nitrogen dioxide (NO2) along the direct solar beam from a moving laboratory. These direct-sun observations provide high photon flux and enable measurements of vertical column densities (VCDs) with geometric air mass factors, high temporal resolution of 2 s and spatial resolution of 5–19 m. It is shown that the instrument line shape (ILS) of the FTS is independent of the azimuth and elevation angle pointing of the solar tracker. Further, collocated measurements next to a high-resolution FTS at the National Center for Atmospheric Research (HR-NCAR-FTS) show that the CU mobile SOF measurements of NH3 and C2H6 are precise and accurate; the VCD error at high signal to noise ratio is 2–7 %. During the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) from 21 July to 3 September 2014 in Colorado, the CU mobile SOF instrument measured median (minimum, maximum) VCDs of 4.3 (0.5, 45) × 1016 molecules cm−2 NH3, 0.30 (0.06, 2.23) × 1016 molecules cm−2 NO2 and 3.5 (1.5, 7.7) × 1016 molecules cm−2 C2H6. All gases were detected in larger 95 % of the spectra recorded in urban, semi-polluted rural and remote rural areas of the Colorado Front Range. We calculate structure functions based on VCDs, which describe the variability of a gas column over distance, and find the largest variability for NH3. The structure functions suggest that currently available satellites resolve about 10 % of the observed NH3 and NO2 VCD variability in the study area. We further quantify the trace gas emission fluxes of NH3 and C2H6 and production rates of NO2 from concentrated animal feeding operations (CAFO) using the mass balance method, i.e., the closed-loop vector integral of the VCD times wind speed along the drive track. Excellent reproducibility is found for NH3 fluxes and also, to a lesser extent, NO2 production rates on 2 consecutive days; for C2H6 the fluxes are affected by variable upwind conditions. Average emission factors were 12.0 and 11.4 gNH3 h−1 head−1 at 30 °C for feedlots with a combined capacity for ∼ 54 000 cattle and a dairy farm of ∼ 7400 cattle; the pooled rate of 11.8 ± 2.0 gNH3 h−1 head−1 is compatible with the upper range of literature values. At this emission rate the NH3 source from cattle in Weld County, CO (535 766 cattle), could be underestimated by a factor of 2–10. CAFO soils are found to be a significant source of NOx. The NOx source accounts for ∼ 1.2 % of the N flux in NH3 and has the potential to add ∼ 10 % to the overall NOx emissions in Weld County and double the NOx source in remote areas. This potential of CAFO to influence ambient NOx concentrations on the regional scale is relevant because O3 formation is NOx sensitive in the Colorado Front Range. Emissions of NH3 and NOx are relevant for the photochemical O3 and secondary aerosol formation.
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De Araujo, Haroldo Ferreira, Paulo Ademar Martins Leal, Thais Queiroz Zorzeto, Pâmela Santaguita Betin, Eduardo Fernandes Nunes und Guilherme Francisco Plana Servilha. „ALTERAÇÕES MICROMETEOROLÓGICAS EM AMBIENTES PROTEGIDOS CULTIVADOS COM MINITOMATE ORGÂNICO“. IRRIGA 21, Nr. 2 (18.06.2018): 226. http://dx.doi.org/10.15809/irriga.2016v21n2p226-238.
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ALTERAÇÕES MICROMETEOROLÓGICAS EM AMBIENTES PROTEGIDOS CULTIVADOS COM MINITOMATE ORGÂNICO HAROLDO FERREIRA DE ARAÚJO1; PAULO ADEMAR MARTINS LEAL2; THAIS QUEIROZ ZORZETO3; EDUARDO FERNANDES NUNES4; PÂMELA SANTAGUITA BETIN5 E GUILHERME FRANCISCO PLANA SERVILHA5 1 Eng. Agrônomo, Pesquisador Doutor, Faculdade de Engenharia Agrícola, FEAGRI/UNICAMP, Av. Cândido Rondon, 501 - Cidade Universitária, Campinas - SP, 13083-875, Fone: (19) 3521-1123, haroldfa@gmail.com2 Eng. Agrícola, Prof. Doutor, Faculdade de Engenharia Agrícola, FEAGRI/UNICAMP, Campinas-SP; E-mail: paulo.leal@ggo.unicamp.br3 Engª. Agrícola, Doutor (a), FEAGRI/UNICAMP, Campinas-SP; E-mail: thaisqz@uol.com.br4 Eng. Telecomunicações, Doutor em Eng. Agrícola, FEAGRI/UNICAMP, Campinas-SP; E-mail: nunes.r4f@gmail.com5 Eng. Agrícola, Graduandos, FEAGRI/UNICAMP, Campinas-SP; E-mails: pamela_betin@hotmail.com e guilhermeservilha@gmail.com 1 RESUMO Várias são as tecnologias utilizadas para a modificação das variáveis meteorológicas em ambiente protegido, porém as alterações e a resposta das culturas sob essas modificações devem ser estudadas. Assim, objetivou-se avaliar as alterações das variáveis meteorológicas em horários sinóticos em diferentes alturas no perfil vertical do centro geométrico de casas de vegetação com diferentes sistemas (resfriamento evaporativo, ventilação mecânica e sombreamento), e cultivadas com minitomate orgânico. Analisaram-se dados de radiação solar, temperatura e umidade relativa do ar, sendo estas últimas nas alturas de 1, 2 e 3 m do piso, em horários sinóticos intermediários (3, 9, 15 e 21 horas) coletados nos diferentes ambientes. A partir dos resultados, notou-se que o microclima em ambientes protegidos somente com malhas termorrefletoras, pode ser caracterizado por um sensor na área de produção no perfil vertical entre 1 e 2 m e outro no bolsão térmico. A associação dos sistemas automatizados de resfriamento evaporativo, ventilação mecânica e tela termorrefletora, permitiram que a temperatura máxima e a umidade relativa do ar mínima fossem mantidas em um nível adequado. Os ambientes com tela termorrefletora móvel foram eficientes na atenuação da radiação solar global diária para a cultura. Palavras–chave: Graus tecnológicos, tela de sombreamento, controle automatizado, cultivo orgânico. ARAÚJO, H. F.; LEAL, P. A. M.; ZORZETO, T. Q.; NUNES, E. F.; BETIN, P. S.; SERVILHA, G. F. PMETEOROLOGICAL VARIABLES IN GREENHOUSES CULTIVATED WITH ORGANIC TOMATO 2 ABSTRACT There are several technologies used for modification of the micrometeorological variables in greenhouse, but the changes and crop response to these modifications must be studied. The objective was to evaluate changes in micrometeorological air variables air in synoptic times at different heights in vertical profile at the geometric center of greenhouses with different systems (evaporative cooling, mechanical ventilation and shading) and cultured cultures grown with organic minitomate. Analyzed data of sSolar radiation, temperature and relative humidity data were assessed, the latter being thewith heights of 1, 2 and 3 m from the floor in intermediate synoptic times (3, 9, 15 and 21 hours) collected in different greenhouses. The results showed that the microclimate in greenhouses with thermal reflector screens meshes could be characterized as a sensor in the production area of the vertical profile between 1 and 2 m and other thermal pocket with readings from day to night of intermediate synoptic hours. The combination of automated evaporative cooling systems, ventilation and thermal reflector screen, allowed the maximum temperature and the relative humidity of minimum air were kept in a desired amplitude control. The mobile thermal reflector screen greenhouses were effective in the attenuation of daily solar radiation, while setting a fixed thermal reflector screen recorded values below the limit for trophic culture. Keywords: Technological Degrees, shade cloth, automated control, organic production.
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Dadios, Elmer P. „Selected Papers from HNICEM 2005“. Journal of Advanced Computational Intelligence and Intelligent Informatics 10, Nr. 2 (20.03.2006): 135. http://dx.doi.org/10.20965/jaciii.2006.p0135.
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HNICEM is a biennial international conference of experts in the fields of Robotics, Nanotechnology, Information Technology, Control and Communication, Environment, and Management. This special issue presents 11 articles selected from HNICEM 2005 that will provide valuable references for researchers and practitioners. The first article presents new content-based image retrieval based on the visual keys concept. Visual keys are defined as representative regions extracted from an image database and are constructed using image feature clustering. The second article presents interactive video recording and playback technique originally developed for biomedical multimedia training. The third article proposes techniques for determining motion parameters based on complex number expression of the rotation matrix. The fourth article studies the learning behavior of Genetic Algorithm and its potential in real time non-linear control. The effects of different parameters used in the GA for its learning are analyzed. The fifth article presents a Coordinated Hybrid Agent (CHA) framework for the control of Multi-Agent Systems (MASs) applied to a heterogeneous multi-agent such as a mobile robot, an overhead crane, and a robot manipulator. The sixth article presents an algorithm that emulates human inference in deducing root causes, avoiding intermediary causes and anticipating subsequent moves. The seventh article proposes a technique to create Intelligent Distributed Robotic Systems (IDRS) that show smart behavior using a wrapper-components approach. The eighth article presents an autonomous mobile robot with neural network (NN) vision that searches for and collects golf balls in an open or indoor golf driving range. The ninth article demonstrates the technological benefits of miniaturizing machine tools in the context of machine stiffness and accuracy. It also presents the design philosophy and configuration of a 4-axis miniaturized vertical machining center with a positioning accuracy of 4 to 10nm. The tenth article investigates a new type of ion exchanger for high ion exchange capacity (IEC) and rapid ion exchange velocity. Experimental results demonstrate the performance of polystyrene nanofiber ion exchangers (PSNIE) and cation exchanger fiber (CEF). The eleventh and last article presents the architectural design of a Multiservice Provisioning Platform (MSPP) for WiMAX over SONET/SDH. It involves networking existing technologies to deliver a solution that caters to a unique situation favoring wireless access networks to a fully cabled system. We extend our warmest thanks and deepest gratitude to the distinguished authors and reviewers who have contributed to this special issue for their outstanding contributions and cooperation. We are also grateful to Prof. Toshio Fukuda and Prof. Kaoru Hirota, chief editors of JACIII, for inviting me to serve as Guest Editor of this Journal.
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Meier, Andreas Carlos, Anja Schönhardt, Tim Bösch, Andreas Richter, André Seyler, Thomas Ruhtz, Daniel-Eduard Constantin et al. „High-resolution airborne imaging DOAS measurements of NO<sub>2</sub> above Bucharest during AROMAT“. Atmospheric Measurement Techniques 10, Nr. 5 (22.05.2017): 1831–57. http://dx.doi.org/10.5194/amt-10-1831-2017.
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Abstract. In this study we report on airborne imaging DOAS measurements of NO2 from two flights performed in Bucharest during the AROMAT campaign (Airborne ROmanian Measurements of Aerosols and Trace gases) in September 2014. These measurements were performed with the Airborne imaging Differential Optical Absorption Spectroscopy (DOAS) instrument for Measurements of Atmospheric Pollution (AirMAP) and provide nearly gapless maps of column densities of NO2 below the aircraft with a high spatial resolution of better than 100 m. The air mass factors, which are needed to convert the measured differential slant column densities (dSCDs) to vertical column densities (VCDs), have a strong dependence on the surface reflectance, which has to be accounted for in the retrieval. This is especially important for measurements above urban areas, where the surface properties vary strongly. As the instrument is not radiometrically calibrated, we have developed a method to derive the surface reflectance from intensities measured by AirMAP. This method is based on radiative transfer calculation with SCIATRAN and a reference area for which the surface reflectance is known. While surface properties are clearly apparent in the NO2 dSCD results, this effect is successfully corrected for in the VCD results. Furthermore, we investigate the influence of aerosols on the retrieval for a variety of aerosol profiles that were measured in the context of the AROMAT campaigns. The results of two research flights are presented, which reveal distinct horizontal distribution patterns and strong spatial gradients of NO2 across the city. Pollution levels range from background values in the outskirts located upwind of the city to about 4 × 1016 molec cm−2 in the polluted city center. Validation against two co-located mobile car-DOAS measurements yields good agreement between the datasets, with correlation coefficients of R = 0.94 and R = 0.85, respectively. Estimations on the NOx emission rate of Bucharest for the two flights yield emission rates of 15.1 ± 9.4 and 13.6 ± 8.4 mol s−1, respectively.
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Alekseev, D. S. „Russian Strategy for Eurasian Integration: Key Elements, Determinants and Prospects for Development“. Moscow University Bulletin of World Politics 12, Nr. 4 (20.12.2020): 3–39. http://dx.doi.org/10.48015/2076-7404-2020-12-4-3-39.
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Eurasia is gradually turning into the point of intersection of various longterm political and economic initiatives undertaken by the leading actors of contemporary international relations, including the Russian Federation, the European Union, the United States and the People’s Republic of China. This trend compounded by a complicated dynamics of integration and disintegration processes in the post-Soviet states further exacerbates tensions in the region, already fraught with conflict. It also poses additional obstacles to the projects of Eurasian integration, promoted by the Russian Federation. In order to provide a better understanding of the specificities and prospects of Russia’s initiatives, the paper examines the origins and the evolution of the Russian strategy of Eurasian integration, and identifies its key elements. The author concludes that fundamental principles of the Russian strategy for reshaping the post-Soviet states have been laid down during the presidency of B.N. Yeltsin and were merely adjusted to meet certain political, social and economic changes both in Russia and abroad. These principles include: 1) commitment to the idea of a multipolar world; 2) creation of supranational Eurasian economic institutions to multiply the economic potential of member-states; 3) prevention of a change of political regimes in neighboring countries if they can bring to power anti-Russian groups; 4) establishment of closer links with China, especially on political, economic and security issues; 5) formation of a new center of political gravity in Eurasia through expanding the capacities of regional political and military organizations which would complement integration processes and ensure regional security. The paper shows that amid growing international tensions in the second half of 2010s the Russian integration initiatives have become increasingly focused on geostrategic, political and military issues. In that regard, the author concludes that, although the development of the Eurasian integration projects enables a wide range of horizontal and vertical economic linkages between the Eurasian Economic Union (EAEU) memberstates, overtly competitive nature of both the Russian and the Western states’ strategies increases the conflict potential of the region. In the absence of alternative approaches, this conflict could not only become a potential source of new tensions between Russia and the West, but also threatens to reverse the current integration processes within the EAEU. The author emphasizes that the abandonment of excessively politicized and ideologized policies both in Russia and in the Western states, which prevents political elites from finding compromises and developing alternative approaches, is the only way to improve the situation in the Eurasian region.
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Abankina, Tatiana V., Galina M. Ksynkina und Elena A. Nikolayenko. „Dynamics of the Cultural Benefits Provision to the Russian Population (2000—2019)“. Observatory of Culture 18, Nr. 1 (24.05.2021): 4–21. http://dx.doi.org/10.25281/2072-3156-2021-18-1-4-21.
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The article studies the dynamics of the cultural benefits provision to the Russian population from the point of view of the main functional types in the period of 2000—2019, and develops proposals to overcome the existing imbalances. The study is aimed at determining the composition of indicators that characterize the population’s provision with conditions and services in the field of culture; forming a database of five functional types for the period of 2000—2019; selecting the methods of analysis, as well as analyzing the dynamics of the cultural benefits provision to the Russian population; assessing the positive effects and negative consequences of the cultural institutions network optimization.To this end, the article analyzes the statistical data of the Main Information and Computing Center of the Ministry of Culture of Russia, examines the legislative acts regulating the state guarantees of providing the population with cultural benefits. For each functional type (theaters, concert organizations and independent groups, museums, libraries, cultural and leisure institutions), the authors select the indicators that characterize conditions and services in the field of culture and compare them with the indicators of attendance and demand for the services by the population. The article applies an indicative model using the methods of horizontal (temporal), vertical (structural) comparative analysis. There is revealed that, firstly, the dynamics of the cultural benefits provision to the Russian population during the specified period was uneven in terms of functional types; secondly, the measures to improve the efficiency of cultural budget expenditures led to some positive changes in the conditions of provision. At the same time, there were certain imbalances in the form of a decrease in the provision of cultural benefits to the population and reduced opportunities for participation in cultural life due to some unreasonable optimization of the network of libraries and cultural and leisure institutions. The study concludes that the identified negative trends can be neutralized by creation of new cultural development centers, active introduction of mobile forms of cultural services and inclusive forms of working with people with special needs, modern digital technologies, development of cultural and educational tourism, volunteerism.
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Whitney, Michael M., und J. S. Allen. „Coastal Wind-Driven Circulation in the Vicinity of a Bank. Part II: Modeling Flow over the Heceta Bank Complex on the Oregon Coast“. Journal of Physical Oceanography 39, Nr. 6 (01.06.2009): 1298–316. http://dx.doi.org/10.1175/2008jpo3967.1.
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Abstract This study investigates wind-driven circulation in the vicinity of the Heceta Bank complex along the Oregon shelf. Numerical experiments forced with steady winds (0.1 Pa) are conducted; upwelling and downwelling cases are compared. The asymmetric bank bathymetry is the only configurational difference from the symmetric bank runs analyzed in Part I (Whitney and Allen). Upwelling-favorable winds generate an upwelling front and southward baroclinic jet. Model results indicate the upwelling jet is centered on the 100-m isobath along the straight shelf. The jet follows this isobath offshore around the northern part of the bank but separates from sharply turning isobaths in the southern half and flows over deeper waters. The jet turns back toward the coast farther downstream. Inshore of the main jet, currents reverse and flow back onto the bank. These reversed currents turn southward again (at the bank center) and join a secondary southward coastal upwelling jet. This secondary coastal jet converges with the stronger main jet farther downstream. Upwelling is intense at the northern bank edge near the coast, where a dense water tongue is advected over the bank. Upwelling also is strong on the southern bank half where the flow turns and reverses. Other areas of the bank have reduced upwelling or even downwelling during upwelling-favorable winds. Downwelling-favorable winds drive a near-bottom density front and a northward jet. The slower downwelling jet flows along the 130-m isobath over the straight shelf. The jet departs from isobaths over the southern bank half and follows a straighter path over shallower waters. There are no reversed currents over the bank. The bank is an area of reduced downwelling. Some of the differences in the evolution of the current and density fields are linked to fundamental differences between the upwelling and downwelling regimes; these are anticipated by the symmetric bank results of Part I. Other differences arise because of the bank asymmetry and opposite flow directions over the bank. The lowest-order depth-averaged across-stream momentum balance remains geostrophic over the bank. Advection, ageostrophic pressure gradients, wind stress, and bottom stress all are important in the depth-averaged alongstream momentum balance over the Heceta Bank complex. Both across-shelf and alongshelf density advection are important. Barotropic potential vorticity is not conserved over the bank, but the tendency for relative vorticity changes and depth changes to partially counter each other influences the different paths of the upwelling and downwelling jets. There are several regions of active upwelling and downwelling over the bank. In these areas, vertical velocities at the top of the bottom boundary layer are linked to topographic upwelling and downwelling and Ekman pumping. There is considerable spatial variability in the currents, densities, and dynamics over the Heceta Bank complex.
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Silva, João B. C., Walter E. Medeiros und Valéria C. F. Barbosa. „Gravity inversion using convexity constraint“. GEOPHYSICS 65, Nr. 1 (Januar 2000): 102–12. http://dx.doi.org/10.1190/1.1444701.
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We present a constraint which incorporates in the geophysical inverse problem a priori information about the source convexity. Two kinds of convexity are considered: directional convexity, defined as the attribute of a body being intersected at most at two points by a straight line with a fixed spatial orientation, and global convexity, defined as the attribute of a body being intersected at most at two points by any arbitrarily oriented straight line. The interpretation model consists of several juxtaposed 2-D prisms whose positions, widths, and physical property are established by the interpreter. The depth to the top and the thickness of each prism are the parameters to be determined. The directional convexity is incorporated by minimizing a functional which expresses the number of times that several lines, parallel to a given direction and spaced at regular intervals, intersect the interpretation model. On the other hand, the global convexity is introduced in an algorithmic way by constraining the depths to the top and to the bottom of each prism to be, respectively, smaller or greater than the average of the depths to the top or to the bottom of the adjacent prisms. The use of the presented convexity contraint is demonstrated using synthetic gravity data produced by an isolated source. We found that convexity constraints (either directional along the horizontal axis or global) alone are insufficient to produce strongly stable solutions, although they reduce substantially the solution instability. Despite the “slight” instability, the directional convexity constraint leads to a reasonable delineation of the source shape and produces a better resolution of its base as compared with the inverse method imposing smoothness constraints on the top and bottom surfaces of the anomalous source. The potential use of the convexity constraint is the possibility of combining it with other constraints to produce geologically meaningful solutions. As an example, the global convexity was combined with the minimum moment of inertia of the anomalous masses about a vertical axis passing through its center of mass. This combination allowed introducing a priori information about a diapir shape. This is important because a maximum spread at the diapir middle portion indicates that it ascended like a viscous bubble in an isotropic medium. On the other hand, a spread located at its top indicates that the host medium is mechanically anisotropic, exhibiting horizontal planes of weakness where the mobile material was forced into. So, this combination of constraints alows introducing a priori information about the diapir emplacement. The combination of global convexity and minimum moment of inertia may also be applied to isolated intrusions, as illustrated with the real gravity anomaly produced by the granitic body of Castelsarrasin, in the Aquitaine Basin, France. The estimated source has its top located between 0.45 and 0.57 km from the surface, a base 6.4 km deep, and center of mass at a depth of 3.5 km, which agree reasonably with a priori geological and geophysical information about the body.
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Dreaden, T. J., A. W. Black, S. Mullerin und J. A. Smith. „First Report of Diplodia quercivora Causing Shoot Dieback and Branch Cankers on Live Oak (Quercus virginiana) in the United States“. Plant Disease 98, Nr. 2 (Februar 2014): 282. http://dx.doi.org/10.1094/pdis-07-13-0736-pdn.
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In September 2010, live oak (Quercus virginiana Mill.) trees in an Alachua County, FL, shopping center parking lot were observed with shoot dieback and cankers on small branches. Isolations were made from canker margins by surface sterilizing tissue in 2.5% sodium hypochlorite and plating on potato dextrose agar (PDA) and incubating at 23°C. Fungi morphologically similar to Diplodia quercivora Linaldeddu & A.J.L. Phillips (mycelium initially velvety and white and later turning pale to dark olivaceous and grayish in reverse) were consistently isolated from symptomatic tissue (2). The two loci used by Linaldeddu et al. (2) in the description of D. quercivora were sequenced to identify a representative isolate (PL1345) as D. quercivora. The internal transcribed spacer (ITS) (GenBank Accession No. KF386635) and translation factor 1-alpha (EF-1α) (KF386636) regions were amplified and sequenced using primers ITS1F/ITS4 (3) and EF1-728F/EF1-986R (1). BLASTn searches of the two sequences resulted in 99% (467 of 469 and 257 of 259, respectively) homology with D. quercivora CBS 133852, confirming the fungal isolates' identity as D. quercivora. In October 2011, Koch's postulates were verified by inoculating, repeated twice, three Q. virginiana saplings (stem diameters, 12 to 14 mm; at inoculation sites approximately 50 mm above soil line) with isolate PL1345. Agar plugs (3 × 3 mm) taken from the margin of a 12-day-old culture on PDA were inserted into flaps in the stems made by a sterile blade with the mycelia facing the cambial tissue. One negative control tree was mock inoculated with a sterile PDA plug. All inoculation sites were sealed with Parafilm and maintained in a greenhouse (19 to 29°C). Trees were assessed for symptoms 90 days after inoculation. External bleeding was noted on all but one tree, and all flaps became necrotic. Pycnidia were observed on the outer surface of the flap on one inoculated tree. Negative controls showed no bleeding and their tissue flaps remained alive. Vertical length of phloem necrosis and percent of stem girdling were measured after removing the bark. Mean necrotic length and percent girdling for inoculated saplings were 48 mm (standard error [SE] = 10.6) and 26.6% (SE = 5.7) for the first inoculation and 46 mm (SE = 17) and 25% (SE = 5) for the second, respectively. Controls showed no internal necrosis and all produced healthy callus tissue at inoculation sites. Two of the pathogen-inoculated trees per inoculation were sampled and the pathogen was re-isolated from each. Recovered fungal isolates were confirmed as D. quercivora based on morphology and 100% ITS sequence homology to PL1345. D. quercivora was first described as causing shoot dieback and cankers on Q. canariensis in Tunisia and was found to be pathogenic to three additional Mediterranean oak species, Q. ilex, Q. pubescens, and Q. suber (2). To our knowledge, this is the first report of D. quercivora causing cankers on Q. virginiana and the first report of the fungus outside of Tunisia. Given the damage this pathogen has caused there, efforts to monitor the spread of this disease would seem warranted. More research is needed to assess the risk this pathogen poses to North American oaks, however. References: (1) I. Carbone et al. Mycologia 91:553, 1999. (2) B. T. Linaldeddu et al. Mycologia 105:1266, 2013. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.
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Onofre, Rubiliza DC, und Rene Louie C. Gutierrez. „Orbital Floor Fracture Reconstruction Using Conchal Auricular Cartilage Graft“. Philippine Journal of Otolaryngology-Head and Neck Surgery 25, Nr. 2 (03.12.2010): 42–45. http://dx.doi.org/10.32412/pjohns.v25i2.635.
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Orbital wall fractures result from external impact injuries which cause an abrupt increase in intraorbital pressure.1 Patients usually present to the emergency room with periorbital swelling and limited eye movements, with or without changes in vision. Relatively common in the Philippines, these fractures are frequently caused by violent assault followed by vehicular accidents involving motorcycles.2 Among 119 maxillofacial trauma cases seen and treated by the Department of Otorhinolaryngology of the East Avenue Medical Center from 2008-2009, 42 were diagnosed as cases of orbital fractures with 36% having concomitant involvement of the orbital floor. Various techniques in diagnosis and treatment developed in the past 20 years, each having its own strengths and weaknesses. The challenge of choosing which among these methods will best achieve the goals of function and aesthetics always confronts surgeons, particularly in a developing country setting.
We present a case of bilateral orbital floor fractures with diplopia repaired with conchal auricular cartilage graft in a 22 year old female.
CASE REPORT
A 22 year old female was immediately brought to our emergency room following a head-on collision with an Asian utility vehicle while driving a motorcycle without a helmet. She was conscious and coherent with stable vital signs.
On examination, contusion hematomas were noted over both periorbital areas. Visual acuity was 20/30 OD and 20/40 OS with bilateral limitations of extraocular muscle movement. Bilateral ocular pressures were measured at 14.6 mmHg. Craniofacial CT Scans revealed linear frontal bone fractures with subdural hemorrhages and pneumocephalus in the frontal area, fractures of the calvarial bones, lateral orbital walls, inferior orbital rims and orbital floors (Figure 1). A mannitol drip was started for the hemorrhage.
She developed a persistent headache and binocular vertical diplopia with monocular diplopia, OS on the left gaze accompanied by pain on lateral left duction. Visual acuity was 20/25 OU. On the 17th hospital day, she underwent open reduction and internal fixation of multiple facial fractures using titanium plates and screws with reconstruction of both orbital floors using conchal cartilage autografts. The right eye diplopia resolved on the third postoperative day while the diplopia on left lateral downward gaze in the left eye resolved from the ninth postoperative day until the day of discharge.
There was complete resolution of diplopia and improvement in visual acuity to 20/20 OD and 20/25 OS on follow up at one year.
DICUSSION
Orbital floor fractures are relatively common midfacial injuries encountered in urban areas2 and were first described by Smith and Regan in 1957.1 Since then, many articles have been written about their diagnosis and treatment, including indications and optimal time for surgery as well as optimal surgical methods.1 Epidemiological studies reveal that despite different settings, the majority of cases involve the young male population with violent assault as the most prominent etiology accounting for 37.8% of orbital blowout fractures; motor vehicle accidents came in at second with 17.6%.; with the remaining fractures resulting from athletics (14.1%).2 To our knowledge, local reports have not been published but similarities in profile can be deduced.
Orbital floor fractures, also known as blowout fractures, imply that the orbital rims have remained intact, whereas one or more walls of the orbit, typically the floor has fractured.3 Orbital floor fractures can be classified into pure and impure according to extent of bone involvement (Table 1). Pure blowout fractures are fractures of the floor not involving the rim while impure blowout fractures have rim extension.3 Pure orbital floor fractures are further classified as trapdoor or non-trapdoor. Trapdoor fractures are those in which either edge of the inferior orbital wall is attached to its original position, while non-trapdoor fractures are those in which the inferior orbital wall is completely separated from its original position and the periorbital tissue has prolapsed into the maxillary sinus1 (Figure 2). These fractures can be also be classified by location: anterior, posterior and anteroposterior1,4 (Figure 3). Our patient presented with non trapdoor type orbital floor fractures measuring 10 x 4 mm on the right and 10 x 5mm on the left.
Patients with orbital floor fractures often complain of blurred vision and pain on eye movement. Physical examination also elicits diplopia, accompanying limitation of eye movement and enophthalmos on the affected side. These signs and symptoms are due to (1) herniation of orbital contents with concomitant partial atrophy of extraocular muscles and to (2) an increase in the volume of the orbital cavity with possible compression of the optic nerve.4 Because of these features, orbital floor fractures are classified as both Otorhinolaryngologic and Ophthalmologic emergencies that warrant immediate surgical treatment especially if the patient presents with blurred vision.3,5
Confirmatory imaging studies help locate and assess the extent of orbital floor injury. These include radiographs and computed tomography of the facial bones. The commonly used radiograph is the chin-to-nose or Water’s view. This gives a view of the whole orbital area and may reveal a pathognomonic “tear drop” sign, seen as an elliptical opacity underneath the inferior orbital rim, that represents orbital contents, usually orbital fat, that herniated through the fracture.1,3 However, facial computed tomography is still the most useful imaging tool in assessing orbital floor fractures.1,2,3,4 It is usually requested without contrast using 3 different cuts: coronal, axial and sagittal. Coronal cuts reveal discontinuity of the inferior orbital rims with concomitant soft tissue sublaxation; axial cuts present the extent of areas involved while sagittal cuts help locate if the fracture is anterior, posterior or anteroposterior.1,4
The goal of surgical repair in orbital floor fractures is two-fold: to reposition herniated orbital fat and tissue back in the orbit; and to reconstruct the traumatic defect.4 Approaches are via open surgery (subciliary or transconjunctival) or endoscopic (transantral), (Table 2). The open transorbital approach is currently regarded as the mainstream method for reduction of blowout fractures of the inferior orbital wall. It is useful for releasing incarcerated soft tissue, as dissecting all soft tissue around the fracture area is necessary.1 Post operative complications include ectropion and unsightly scars, but these rarely occur in the hands of experienced surgeons.5 Endoscopic repair, usually via a transantral approach, can provide surgeons with several advantages over conventional external repair. These include excellent visualization of the medial and inferior walls of the orbit; easy access to maxillary bone (avoiding or minimizing use of intraocular alloplastic implants); virtual elimination of significantly visible facial scarring and eyelid complications; and performing the procedure under local anesthesia, making intra-operative evaluation of ocular movements and diplopia possible.5,6 A transorbital approach has the advantage of releasing incarcerated orbital tissue, while, in contrast, simply lifting the orbital tissue upward in a transantral approach may aggravate the incarceration1 (Table 2). In this patient, the open approach was used because a mid-facial de-gloving was necessary to access other fractures.
The repair of orbital floor fractures involves many techniques, and adequate knowledge and skill is needed to perform any of these techniques employing careful judgment and analysis in formulating a plan that will fit the patient’s needs. As a general principle, the orbital complex is reconstructed by aligning its fractured parts with adjacent stabilized or intact structures.10 Familiarity with the complex shape of the orbital walls is important in repair. In the case of the orbital floor, it gently concaves inferolaterally, turning convex medially to posteriorly, assuming an S-shape configuration. 1,3 The posterior part of the floor is farthest from the inferior orbital rim with the infraorbital nerve coursing thru it makes it vulnerable and weak to the extensive forces absorbed when applied into the orbital area.1,3,10 This explains why posterior orbital floor fractures occur as non-trapdoor types and are difficult to expose. The orbital contents are positioned accurately and precisely into the orbit making any change in volume affect eye function. It is important to assess eye function first as it may give the examiner an idea of the extent of injury to the orbital floor. Indications for repair include diplopia, nonresolving oculocardiac reflex with entrapment (bradycardia, heartblock vomiting, nausea and syncope), fracture involving >50% of the orbital floor, and early enophthalmos or hypoglobus causing facial asymmetry.11 These signs and symptoms elicited during physical examination with documentation of the location of fracture through diagnostic imaging warrant early repair since herniated soft orbital tissue can atrophy within 2-3 weeks post trauma.4
The types of grafts/implants used to span the defects of orbital floor fractures are divided into alloplastic and autogenous implants7 (Table 3). Autogenous grafts include bone, cartilage, and fascia. Alloplastic implants can be divided into nonabsorbable types, such as those made of silicone, polytef, hydroxyapatite, tantalum mesh, or titanium, and absorbable types, including those made of polyglactin or gel film. Repair of the orbital floor defect is mandatory if the defect measures at least 50% of the size of the orbital floor bone. The ideal implant must be nonreactive, provide good structural support, be easily positioned, and be readily available.1,2,3,4 In this case the surgeon utilized conchal cartilage grafts. This graft can be used in repairing defects as large as 2 x 2mm. It advantages over other autogenous grafts include having a shape similar to the orbital floor, ease of harvest, malleability and limited morbidity at the donor site.4
Autogenous tissue grafts, i.e. bone or cartilage, are preferred over alloplastic grafts in the repair of isolated orbital fractures similar to this case.10 Grafts (especially bone) should be secured to avoid displacement or migration and improve graft survival. Complete dissection of the fracture is necessary to identity the intact bone on all side of the fracture since these will be used as alignments when placing the graft. In the case of an orbital floor fracture, the posterior portion of the intact bone will serve as a guide to internal orbital reconstruction. The graft should be placed in inclined position just behind the inferior orbital rim to reach the intact posterior bone.3,10 Placing the graft based on correct anatomic position during reconstruction is of more significance rather than using the globe position as basis in volume restoration.10 It is a must to perform duction tests following graft placements and compare these to baseline duction test prior to surgery.9,10 This will help the surgeon distinguish if the stiff duction test is caused by edema from impingement of the musculofibrous ligament system by the graft material.10
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Acknowledgement
The authors would like to thank Dr Natividad Almazan and Dr. Felix Nolasco for their encouragement and support; and the resident doctors of the Department of ORL-HNS for their help in making this paper.