Orientation Of Coordinate Systems Research Articles

Determination of Geoelectrical Strike To Investigate The Geological Structures In Surabaya And Gresik Areas

The Magnetotelluric data acquisition is performed with a certain coordinate system orientation, thus the possibility of the field measurement data would be not proper with the geological strike direction. Therefore, the information of geoelectrical strike is needed to enhance the quality of Magnetotelluric data interpretation where if the data had the similar direction with the geological strike thus it will be properly sufficient with the actual subsurface condition. A magnetotelluric study by utilized polar diagram was conducted to analyze the orientation of geoelectrical strike that are correlated with the geological structures in the Surabaya and Gresik areas. However, polar diagram analysis using phase tensor data has an ambiguity of +90° therefore additional analysis is carried out using tipper data. The results showed the geoelectrical strike direction is N315°E and it is slightly similar with the strike trend of geological structures anomaly. Meanwhile, the geological structures is generally characterized by low to medium value of resistivity contrasts around 30-500 ohm.m consisting of the Surabaya Kendeng Fault, Kendeng Kedung Waru Fault, anticline, and other expected faults.

Space-Time Processing of Object Images in Passive Radio Imaging Systems

This paper describes the concept and methods of space-time processing of radio images of small objects in a multiposition radiometer system, which make it possible to increase the performance of this system. The spatial processing is carried out in each overlook cycle of scanning radiometers in order to determine the spatial coordinates of objects and mutual orientation of coordinate systems. The time processing is carried out in a sequence of overlook cycles of radiometers for determining the trajectory of the objects that change mutual positions.

Decoupled Direct Control of Natural and Power Variables of Doubly Fed Induction Generator for Extended Wind Speed Range Using Feedback Linearization

The electromagnetic torque, stator power, and the grid side converter power outputs of a doubly fed induction generator (DFIG) are differentiated to obtain a feedback linear relationship with the rotor voltage vectors serving as the control inputs. The derived model is such that can allow for a transition of DFIG to operate at low wind speed by shorting its stator terminal to one another. The torque and power quantities are the state variables of the system, which are insensitive to coordinate system orientation. Steady-state models are used to obtain optimal operating regimes with respect to minimal electrical losses. Decoupled torque control is developed by field orientation, while decoupled power control is derived from voltage orientation of the DFIG. Transients originating from transitioning into low wind speed operation are investigated. Robustness of each of the decoupled controllers against parameter variations is investigated by locating the poles of its closed-loop transfer function. The results for a 5-Hp machine are presented.

SU‐E‐T‐689: Effects of Coordinate System Orientation On ICRU Bladder Point Dose

Purpose: To quantify the displacement and dosimetric errors on position of the ICRU bladder point due to coordinate system orientation in gynecological HDR procedures. Methods: Eight patients (23 treatment fractions) receiving HDR brachytherapy for gynecological malignancies were evaluated. Bladder points were placed for each of two coordinate systems (ICRU and applicator) for each patient fraction. The ICRU coordinate system refers to true anatomical orientations (e.g., ant/post) while the applicator coordinate system is transformed (translated and rotated) based on the location and orientation treatment applicator and is used to define prescription points and optimize planned dose distributions. In both cases, the ICRU bladder point definition was used to place the point (most posterior point of foley balloon on lateral image and center of foley balloon on AP image) with differences resulting from definition of coordinate system orientation. The displacement in three dimensions and point dose differences were calculated for each patient fraction. Results: Point displacement of the applicator coordinate system point (Bappl) relative to the ICRU point (BICRU) was 6.3 ± 0.7 mm (mean ± std err) with a range of 1.5 to 12.6 mm, a statistically significant Result. Dosimetrically, dose to Bappl was 7.3 ± 1.6% (mean ± std err) of the prescribed dose higher than BICRU with a range of −7.9 to 24.7%, a statistically and clinically significant Result. This results in an overestimation of bladder dose when using the applicator coordinate system and using ICRU point dose criteria for plan evaluation. Conclusion: Failure to use a true anatomical coordinate system can lead to statistically and clinically significant dosimetric errors in dose to the defined bladder point. Use of the applicator coordinate system to define the bladder point can potentially cause compromises in plan quality in attempting to meet normal tissue dose tolerances evaluated with incorrectly reported doses.

WebSims: A Web-based System for Storage, Visualization, and Dissemination of Earthquake Ground-motion Simulations

Research Article| November 01, 2009 WebSims: A Web-based System for Storage, Visualization, and Dissemination of Earthquake Ground-motion Simulations Kim B. Olsen; Kim B. Olsen Search for other works by this author on: GSW Google Scholar Geoffrey Ely Geoffrey Ely Search for other works by this author on: GSW Google Scholar Author and Article Information Kim B. Olsen Geoffrey Ely Publisher: Seismological Society of America First Online: 09 Mar 2017 Online ISSN: 1938-2057 Print ISSN: 0895-0695 © 2009 by the Seismological Society of America Seismological Research Letters (2009) 80 (6): 1002–1007. https://doi.org/10.1785/gssrl.80.6.1002 Article history First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Kim B. Olsen, Geoffrey Ely; WebSims: A Web-based System for Storage, Visualization, and Dissemination of Earthquake Ground-motion Simulations. Seismological Research Letters 2009;; 80 (6): 1002–1007. doi: https://doi.org/10.1785/gssrl.80.6.1002 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search Synthetic time histories from large-scale three-dimensional dynamic rupture or ground-motion simulations generally constitute large data sets, which typically require hundreds of megabytes, gigabytes or even terabytes of storage capacity (see, e.g., Olsen et al.2008, 2009). For a seismologist analyzing rupture propagation or an earthquake engineer performing seismic hazard analysis, accessing large simulation output can be a tedious and error-prone procedure. For example, manual extractions of synthetic ground-motion records at a few sites of interest, or sliprate functions at desired locations on the fault, are subject to potential misinterpretation of site coordinates, units, or coordinate system orientation.... You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The video technique developed for measuring epicardial strains on guinea pig's left ventricle

Single-plain video used for measurements of epicardial strains is a technique that yields minor interference with the studied mechanical properties of the ventricle. Due to its low temporal resolution, the existing technique is, however, not appropriate for small animals. We questioned whether the technique could be improved enough to cope with higher heart rates and miniaturization necessary for experiments on rats, mice and guinea pigs. Therefore, we developed a high-speed video system and used it for measuring epicardial strains in guinea pig hearts in situ with the open chest. The improvement was achieved in video hardware (camera: Dalsa D6-0256; framegraber: EPIX PIXCI D32) and software, the markers (glowing acrylate crystals; diameter ∼0.15 mm) and illumination (UVA light, OSRAM L). Three markers were attached onto the epicardium in the equatorial region of the left ventricular free wall, 1.5 mm apart, with fibrin glue. From their coordinates, we calculated two-dimensional finite strains with end diastole as the reference point. The accuracy of the displacement measurement of the technique and the error introduced by approximate-visual estimation of the left ventricle coordinate system were evaluated. The accuracy of the displacement measurement was ±1.6 μm and the temporal resolution was 2 ms. Error due to approximate coordinate system orientation was ±3% of the strain amplitude. The typical amplitude of strains was −0.06, −0.11 and 0.04 in circumferential, axial direction and in-plane shear, respectively. The improvements enable us to perform physiologically relevant measurements of epicardial deformations on guinea pig heart.

The coordinate system for jaw movement control

Previously, it was reported that, when 3-D jaw motion during speech is decomposed into its three rotation and three translation components, it consists primarily of rotation and translation within the midsagittal plane [E. Vatikiotis-Bateson and D. J. Ostry, J. Acoust. Soc. Am. 92, 2391(A) (1992)]. Although small in magnitude, two nonsagittal components, roll and yaw, also varied consistently with phonetic context. In this paper, it is shown that the behavior of individual jaw motion components depends in part on the choice of coordinate system orientation. In particular, the use of the occlusal bite plane to orient the jaw may not be appropriate for characterizing the active components of jaw motion during speech. For example, when orientation of the coordinate system is rotated 15–20 deg down from the occlusal plane, the roll component is eliminated. Whether or not the frame or reference for jaw motion is function-specific or purely anatomical is addressed using data from a new study comparing mastication and speech.

Orthogonality of spherical harmonic coefficients

An essentially arbitrary function V( θ, λ) defined on the surface of a sphere can be expressed in terms of spherical harmonics V(θ, Λ) = a ∑ n=1 ∞ ∑ m=0 n p m n (cos θ) (g m n cos mΛ + h m n sin mΛ) where the P n m are the seminormalized associated Legendre polynomials used in geomagnetism, normalized so that 〈[P m n(cos θ) cos mΛ]〉 2 =1/ (2n+1) The angular brackets denote an average over the sphere. The class of functions V( θ, λ) under consideration is that normally of interest in physics and engineering. If we consider an ensemble of all possible orientations of our coordinate system relative to the sphere, then the coefficients g n m and h n m will be functions of the particular coordinate system orientation, but 〈:(g m n) 2〉) = 〈(h m n) 2 = S n/ (2n=1) where S n = ∑ m=0 n [(g m n) 2 + (h m n) 2] for any orientation of the coordinate system ( S n is invariant under rotation of the coordinate system). The averages are over all orientations of the system relative to the sphere. It is also shown that 〈 g m n g l p 〉 = 〈 h m n h l p 〉 = 0 for l ≠ m or p ≠ n and 〈 g m n h l p 〉 = 0 fro all n, m, p, l.